Manual Pages¶

arpaname - translate IP addresses to the corresponding ARPA names¶

Synopsis¶

arpaname {ipaddress …}

Description¶

arpaname translates IP addresses (IPv4 and IPv6) to the corresponding IN-ADDR.ARPA or IP6.ARPA names.

ddns-confgen - ddns key generation tool¶

Synopsis¶

tsig-keygen [-a algorithm] [-h] [-r randomfile] [name]

ddns-confgen [-a algorithm] [-h] [-k keyname] [-q] [-r randomfile] [-s name] [-z zone]

Description¶

tsig-keygen and ddns-confgen are invocation methods for a utility that generates keys for use in TSIG signing. The resulting keys can be used, for example, to secure dynamic DNS updates to a zone or for the rndc command channel.

When run as tsig-keygen, a domain name can be specified on the command line to be used as the name of the generated key. If no name is specified, the default is tsig-key.

When run as ddns-confgen, the generated key is accompanied by configuration text and instructions that can be used with nsupdate and named when setting up dynamic DNS, including an example update-policy statement. (This usage is similar to the rndc-confgen command for setting up command-channel security.)

Note that named itself can configure a local DDNS key for use with nsupdate -l; it does this when a zone is configured with update-policy local;. ddns-confgen is only needed when a more elaborate configuration is required: for instance, if nsupdate is to be used from a remote system.

Options¶

-a algorithm: This option specifies the algorithm to use for the TSIG key. Available choices are: hmac-md5, hmac-sha1, hmac-sha224, hmac-sha256, hmac-sha384, and hmac-sha512. The default is hmac-sha256. Options are case-insensitive, and the “hmac-” prefix may be omitted.
-h: This option prints a short summary of options and arguments.
-k keyname: This option specifies the key name of the DDNS authentication key. The default is ddns-key when neither the -s nor -z option is specified; otherwise, the default is ddns-key as a separate label followed by the argument of the option, e.g., ddns-key.example.com. The key name must have the format of a valid domain name, consisting of letters, digits, hyphens, and periods.
-q (ddns-confgen only): This option enables quiet mode, which prints only the key, with no explanatory text or usage examples. This is essentially identical to tsig-keygen.
-s name (ddns-confgen only): This option generates a configuration example to allow dynamic updates of a single hostname. The example named.conf text shows how to set an update policy for the specified name using the “name” nametype. The default key name is ddns-key.name. Note that the “self” nametype cannot be used, since the name to be updated may differ from the key name. This option cannot be used with the -z option.
-z zone (ddns-confgen only): This option generates a configuration example to allow dynamic updates of a zone. The example named.conf text shows how to set an update policy for the specified zone using the “zonesub” nametype, allowing updates to all subdomain names within that zone. This option cannot be used with the -s option.

delv - DNS lookup and validation utility¶

Synopsis¶

delv [@server] [ [-4] | [-6] ] [-a anchor-file] [-b address] [-c class] [-d level] [-i] [-m] [-p port#] [-q name] [-t type] [-x addr] [name] [type] [class] [queryopt…]

delv [-h]

delv [-v]

delv [queryopt…] [query…]

Description¶

delv is a tool for sending DNS queries and validating the results, using the same internal resolver and validator logic as named.

delv sends to a specified name server all queries needed to fetch and validate the requested data; this includes the original requested query, subsequent queries to follow CNAME or DNAME chains, queries for DNSKEY, and DS records to establish a chain of trust for DNSSEC validation. It does not perform iterative resolution, but simulates the behavior of a name server configured for DNSSEC validating and forwarding.

By default, responses are validated using the built-in DNSSEC trust anchor for the root zone (“.”). Records returned by delv are either fully validated or were not signed. If validation fails, an explanation of the failure is included in the output; the validation process can be traced in detail. Because delv does not rely on an external server to carry out validation, it can be used to check the validity of DNS responses in environments where local name servers may not be trustworthy.

Unless it is told to query a specific name server, delv tries each of the servers listed in /etc/resolv.conf. If no usable server addresses are found, delv sends queries to the localhost addresses (127.0.0.1 for IPv4, ::1 for IPv6).

When no command-line arguments or options are given, delv performs an NS query for “.” (the root zone).

Simple Usage¶

A typical invocation of delv looks like:

delv @server name type

where:

server

is the name or IP address of the name server to query. This can be an IPv4 address in dotted-decimal notation or an IPv6 address in colon-delimited notation. When the supplied server argument is a hostname, delv resolves that name before querying that name server (note, however, that this initial lookup is not validated by DNSSEC).

If no server argument is provided, delv consults /etc/resolv.conf; if an address is found there, it queries the name server at that address. If either of the -4 or -6 options is in use, then only addresses for the corresponding transport are tried. If no usable addresses are found, delv sends queries to the localhost addresses (127.0.0.1 for IPv4, ::1 for IPv6).

name

is the domain name to be looked up.

type

indicates what type of query is required - ANY, A, MX, etc. type can be any valid query type. If no type argument is supplied, delv performs a lookup for an A record.

Options¶

-a anchor-file

This option specifies a file from which to read DNSSEC trust anchors. The default is /etc/bind.keys, which is included with BIND 9 and contains one or more trust anchors for the root zone (“.”).

Keys that do not match the root zone name are ignored. An alternate key name can be specified using the +root=NAME options.

Note: When reading the trust anchor file, delv treats trust-anchors, initial-key, and static-key identically. That is, for a managed key, it is the initial key that is trusted; RFC 5011 key management is not supported. delv does not consult the managed-keys database maintained by named, which means that if either of the keys in /etc/bind.keys is revoked and rolled over, /etc/bind.keys must be updated to use DNSSEC validation in delv.

-b address

This option sets the source IP address of the query to address. This must be a valid address on one of the host’s network interfaces, or 0.0.0.0, or ::. An optional source port may be specified by appending #<port>

-c class

This option sets the query class for the requested data. Currently, only class “IN” is supported in delv and any other value is ignored.

-d level

This option sets the systemwide debug level to level. The allowed range is from 0 to 99. The default is 0 (no debugging). Debugging traces from delv become more verbose as the debug level increases. See the +mtrace, +rtrace, and +vtrace options below for additional debugging details.

-h

This option displays the delv help usage output and exits.

-i

This option sets insecure mode, which disables internal DNSSEC validation. (Note, however, that this does not set the CD bit on upstream queries. If the server being queried is performing DNSSEC validation, then it does not return invalid data; this can cause delv to time out. When it is necessary to examine invalid data to debug a DNSSEC problem, use dig +cd.)

-m

This option enables memory usage debugging.

-p port#

This option specifies a destination port to use for queries, instead of the standard DNS port number 53. This option is used with a name server that has been configured to listen for queries on a non-standard port number.

-q name

This option sets the query name to name. While the query name can be specified without using the -q option, it is sometimes necessary to disambiguate names from types or classes (for example, when looking up the name “ns”, which could be misinterpreted as the type NS, or “ch”, which could be misinterpreted as class CH).

-t type

This option sets the query type to type, which can be any valid query type supported in BIND 9 except for zone transfer types AXFR and IXFR. As with -q, this is useful to distinguish query-name types or classes when they are ambiguous. It is sometimes necessary to disambiguate names from types.

The default query type is “A”, unless the -x option is supplied to indicate a reverse lookup, in which case it is “PTR”.

-v

This option prints the delv version and exits.

-x addr

This option performs a reverse lookup, mapping an address to a name. addr is an IPv4 address in dotted-decimal notation, or a colon-delimited IPv6 address. When -x is used, there is no need to provide the name or type arguments; delv automatically performs a lookup for a name like 11.12.13.10.in-addr.arpa and sets the query type to PTR. IPv6 addresses are looked up using nibble format under the IP6.ARPA domain.

-4

This option forces delv to only use IPv4.

-6

This option forces delv to only use IPv6.

Query Options¶

delv provides a number of query options which affect the way results are displayed, and in some cases the way lookups are performed.

Each query option is identified by a keyword preceded by a plus sign (+). Some keywords set or reset an option. These may be preceded by the string no to negate the meaning of that keyword. Other keywords assign values to options like the timeout interval. They have the form +keyword=value. The query options are:

+[no]cdflag

This option controls whether to set the CD (checking disabled) bit in queries sent by delv. This may be useful when troubleshooting DNSSEC problems from behind a validating resolver. A validating resolver blocks invalid responses, making it difficult to retrieve them for analysis. Setting the CD flag on queries causes the resolver to return invalid responses, which delv can then validate internally and report the errors in detail.

+[no]class

This option controls whether to display the CLASS when printing a record. The default is to display the CLASS.

+[no]ttl

This option controls whether to display the TTL when printing a record. The default is to display the TTL.

+[no]rtrace

This option toggles resolver fetch logging. This reports the name and type of each query sent by delv in the process of carrying out the resolution and validation process, including the original query and all subsequent queries to follow CNAMEs and to establish a chain of trust for DNSSEC validation.

This is equivalent to setting the debug level to 1 in the “resolver” logging category. Setting the systemwide debug level to 1 using the -d option produces the same output, but affects other logging categories as well.

+[no]mtrace

This option toggles message logging. This produces a detailed dump of the responses received by delv in the process of carrying out the resolution and validation process.

This is equivalent to setting the debug level to 10 for the “packets” module of the “resolver” logging category. Setting the systemwide debug level to 10 using the -d option produces the same output, but affects other logging categories as well.

+[no]vtrace

This option toggles validation logging. This shows the internal process of the validator as it determines whether an answer is validly signed, unsigned, or invalid.

This is equivalent to setting the debug level to 3 for the “validator” module of the “dnssec” logging category. Setting the systemwide debug level to 3 using the -d option produces the same output, but affects other logging categories as well.

+[no]short

This option toggles between verbose and terse answers. The default is to print the answer in a verbose form.

+[no]comments

This option toggles the display of comment lines in the output. The default is to print comments.

+[no]rrcomments

This option toggles the display of per-record comments in the output (for example, human-readable key information about DNSKEY records). The default is to print per-record comments.

+[no]crypto

This option toggles the display of cryptographic fields in DNSSEC records. The contents of these fields are unnecessary to debug most DNSSEC validation failures and removing them makes it easier to see the common failures. The default is to display the fields. When omitted, they are replaced by the string [omitted] or, in the DNSKEY case, the key ID is displayed as the replacement, e.g. [ key id = value ].

+[no]trust

This option controls whether to display the trust level when printing a record. The default is to display the trust level.

+[no]split[=W]

This option splits long hex- or base64-formatted fields in resource records into chunks of W characters (where W is rounded up to the nearest multiple of 4). +nosplit or +split=0 causes fields not to be split at all. The default is 56 characters, or 44 characters when multiline mode is active.

+[no]all

This option sets or clears the display options +[no]comments, +[no]rrcomments, and +[no]trust as a group.

+[no]multiline

This option prints long records (such as RRSIG, DNSKEY, and SOA records) in a verbose multi-line format with human-readable comments. The default is to print each record on a single line, to facilitate machine parsing of the delv output.

+[no]dnssec

This option indicates whether to display RRSIG records in the delv output. The default is to do so. Note that (unlike in dig) this does not control whether to request DNSSEC records or to validate them. DNSSEC records are always requested, and validation always occurs unless suppressed by the use of -i or +noroot.

+[no]root[=ROOT]

This option indicates whether to perform conventional DNSSEC validation, and if so, specifies the name of a trust anchor. The default is to validate using a trust anchor of “.” (the root zone), for which there is a built-in key. If specifying a different trust anchor, then -a must be used to specify a file containing the key.

+[no]tcp

This option controls whether to use TCP when sending queries. The default is to use UDP unless a truncated response has been received.

+[no]unknownformat

This option prints all RDATA in unknown RR-type presentation format (RFC 3597). The default is to print RDATA for known types in the type’s presentation format.

+[no]yaml

This option prints response data in YAML format.

Files¶

/etc/bind.keys

/etc/resolv.conf

dig - DNS lookup utility¶

Synopsis¶

dig [@server] [-b address] [-c class] [-f filename] [-k filename] [-m] [-p port#] [-q name] [-t type] [-v] [-x addr] [-y [hmac:]name:key] [ [-4] | [-6] ] [name] [type] [class] [queryopt…]

dig [-h]

dig [global-queryopt…] [query…]

Description¶

dig is a flexible tool for interrogating DNS name servers. It performs DNS lookups and displays the answers that are returned from the name server(s) that were queried. Most DNS administrators use dig to troubleshoot DNS problems because of its flexibility, ease of use, and clarity of output. Other lookup tools tend to have less functionality than dig.

Although dig is normally used with command-line arguments, it also has a batch mode of operation for reading lookup requests from a file. A brief summary of its command-line arguments and options is printed when the -h option is given. The BIND 9 implementation of dig allows multiple lookups to be issued from the command line.

Unless it is told to query a specific name server, dig tries each of the servers listed in /etc/resolv.conf. If no usable server addresses are found, dig sends the query to the local host.

When no command-line arguments or options are given, dig performs an NS query for “.” (the root).

It is possible to set per-user defaults for dig via ${HOME}/.digrc. This file is read and any options in it are applied before the command-line arguments. The -r option disables this feature, for scripts that need predictable behavior.

The IN and CH class names overlap with the IN and CH top-level domain names. Either use the -t and -c options to specify the type and class, use the -q to specify the domain name, or use “IN.” and “CH.” when looking up these top-level domains.

Simple Usage¶

A typical invocation of dig looks like:

dig @server name type

where:

server

is the name or IP address of the name server to query. This can be an IPv4 address in dotted-decimal notation or an IPv6 address in colon-delimited notation. When the supplied server argument is a hostname, dig resolves that name before querying that name server.

If no server argument is provided, dig consults /etc/resolv.conf; if an address is found there, it queries the name server at that address. If either of the -4 or -6 options are in use, then only addresses for the corresponding transport are tried. If no usable addresses are found, dig sends the query to the local host. The reply from the name server that responds is displayed.

name

is the name of the resource record that is to be looked up.

type

indicates what type of query is required - ANY, A, MX, SIG, etc. type can be any valid query type. If no type argument is supplied, dig performs a lookup for an A record.

Options¶

-4

This option indicates that only IPv4 should be used.

-6

This option indicates that only IPv6 should be used.

-b address[#port]

This option sets the source IP address of the query. The address must be a valid address on one of the host’s network interfaces, or “0.0.0.0” or “::”. An optional port may be specified by appending #port.

-c class

This option sets the query class. The default class is IN; other classes are HS for Hesiod records or CH for Chaosnet records.

-f file

This option sets batch mode, in which dig reads a list of lookup requests to process from the given file. Each line in the file should be organized in the same way it would be presented as a query to dig using the command-line interface.

-k keyfile

This option tells named to sign queries using TSIG using a key read from the given file. Key files can be generated using tsig-keygen. When using TSIG authentication with dig, the name server that is queried needs to know the key and algorithm that is being used. In BIND, this is done by providing appropriate key and server statements in named.conf.

-m

This option enables memory usage debugging.

-p port

This option sends the query to a non-standard port on the server, instead of the default port 53. This option is used to test a name server that has been configured to listen for queries on a non-standard port number.

-q name

This option specifies the domain name to query. This is useful to distinguish the name from other arguments.

-r

This option indicates that options from ${HOME}/.digrc should not be read. This is useful for scripts that need predictable behavior.

-t type

This option indicates the resource record type to query, which can be any valid query type. If it is a resource record type supported in BIND 9, it can be given by the type mnemonic (such as NS or AAAA). The default query type is A, unless the -x option is supplied to indicate a reverse lookup. A zone transfer can be requested by specifying a type of AXFR. When an incremental zone transfer (IXFR) is required, set the type to ixfr=N. The incremental zone transfer contains all changes made to the zone since the serial number in the zone’s SOA record was N.

All resource record types can be expressed as TYPEnn, where nn is the number of the type. If the resource record type is not supported in BIND 9, the result is displayed as described in RFC 3597.

-u

This option indicates that print query times should be provided in microseconds instead of milliseconds.

-v

This option prints the version number and exits.

-x addr

This option sets simplified reverse lookups, for mapping addresses to names. The addr is an IPv4 address in dotted-decimal notation, or a colon-delimited IPv6 address. When the -x option is used, there is no need to provide the name, class, and type arguments. dig automatically performs a lookup for a name like 94.2.0.192.in-addr.arpa and sets the query type and class to PTR and IN respectively. IPv6 addresses are looked up using nibble format under the IP6.ARPA domain.

-y [hmac:]keyname:secret

This option signs queries using TSIG with the given authentication key. keyname is the name of the key, and secret is the base64-encoded shared secret. hmac is the name of the key algorithm; valid choices are hmac-md5, hmac-sha1, hmac-sha224, hmac-sha256, hmac-sha384, or hmac-sha512. If hmac is not specified, the default is hmac-md5; if MD5 was disabled, the default is hmac-sha256.

Note

Only the -k option should be used, rather than the -y option, because with -y the shared secret is supplied as a command-line argument in clear text. This may be visible in the output from ps1 or in a history file maintained by the user’s shell.

Query Options¶

dig provides a number of query options which affect the way in which lookups are made and the results displayed. Some of these set or reset flag bits in the query header, some determine which sections of the answer get printed, and others determine the timeout and retry strategies.

Each query option is identified by a keyword preceded by a plus sign (+). Some keywords set or reset an option; these may be preceded by the string no to negate the meaning of that keyword. Other keywords assign values to options, like the timeout interval. They have the form +keyword=value. Keywords may be abbreviated, provided the abbreviation is unambiguous; for example, +cd is equivalent to +cdflag. The query options are:

+[no]aaflag

This option is a synonym for +[no]aaonly.

+[no]aaonly

This option sets the aa flag in the query.

+[no]additional

This option displays [or does not display] the additional section of a reply. The default is to display it.

+[no]adflag

This option sets [or does not set] the AD (authentic data) bit in the query. This requests the server to return whether all of the answer and authority sections have been validated as secure, according to the security policy of the server. AD=1 indicates that all records have been validated as secure and the answer is not from a OPT-OUT range. AD=0 indicates that some part of the answer was insecure or not validated. This bit is set by default.

+[no]all

This option sets or clears all display flags.

+[no]answer

This option displays [or does not display] the answer section of a reply. The default is to display it.

+[no]authority

This option displays [or does not display] the authority section of a reply. The default is to display it.

+[no]badcookie

This option retries the lookup with a new server cookie if a BADCOOKIE response is received.

+[no]besteffort

This option attempts to display the contents of messages which are malformed. The default is to not display malformed answers.

+bufsize[=B]

This option sets the UDP message buffer size advertised using EDNS0 to B bytes. The maximum and minimum sizes of this buffer are 65535 and 0, respectively. +bufsize=0 disables EDNS (use +bufsize=0 +edns to send an EDNS message with an advertised size of 0 bytes). +bufsize restores the default buffer size.

+[no]cdflag

This option sets [or does not set] the CD (checking disabled) bit in the query. This requests the server to not perform DNSSEC validation of responses.

+[no]class

This option displays [or does not display] the CLASS when printing the record.

+[no]cmd

This option toggles the printing of the initial comment in the output, identifying the version of dig and the query options that have been applied. This option always has a global effect; it cannot be set globally and then overridden on a per-lookup basis. The default is to print this comment.

+[no]comments

This option toggles the display of some comment lines in the output, with information about the packet header and OPT pseudosection, and the names of the response section. The default is to print these comments.

Other types of comments in the output are not affected by this option, but can be controlled using other command-line switches. These include +[no]cmd, +[no]question, +[no]stats, and +[no]rrcomments.

+[no]cookie=####

This option sends [or does not send] a COOKIE EDNS option, with an optional value. Replaying a COOKIE from a previous response allows the server to identify a previous client. The default is +cookie.

+cookie is also set when +trace is set to better emulate the default queries from a nameserver.

+[no]crypto

This option toggles the display of cryptographic fields in DNSSEC records. The contents of these fields are unnecessary for debugging most DNSSEC validation failures and removing them makes it easier to see the common failures. The default is to display the fields. When omitted, they are replaced by the string [omitted] or, in the DNSKEY case, the key ID is displayed as the replacement, e.g. [ key id = value ].

+[no]defname

This option, which is deprecated, is treated as a synonym for +[no]search.

+[no]dnssec

This option requests that DNSSEC records be sent by setting the DNSSEC OK (DO) bit in the OPT record in the additional section of the query.

+domain=somename

This option sets the search list to contain the single domain somename, as if specified in a domain directive in /etc/resolv.conf, and enables search list processing as if the +search option were given.

+dscp=value

This option sets the DSCP code point to be used when sending the query. Valid DSCP code points are in the range [0…63]. By default no code point is explicitly set.

+[no]edns[=#]

This option specifies the EDNS version to query with. Valid values are 0 to 255. Setting the EDNS version causes an EDNS query to be sent. +noedns clears the remembered EDNS version. EDNS is set to 0 by default.

+[no]ednsflags[=#]

This option sets the must-be-zero EDNS flags bits (Z bits) to the specified value. Decimal, hex, and octal encodings are accepted. Setting a named flag (e.g., DO) is silently ignored. By default, no Z bits are set.

+[no]ednsnegotiation

This option enables/disables EDNS version negotiation. By default, EDNS version negotiation is enabled.

+[no]ednsopt[=code[:value]]

This option specifies the EDNS option with code point code and an optional payload of value as a hexadecimal string. code can be either an EDNS option name (for example, NSID or ECS) or an arbitrary numeric value. +noednsopt clears the EDNS options to be sent.

+[no]expire

This option sends an EDNS Expire option.

+[no]fail

This option indicates that named should try [or not try] the next server if a SERVFAIL is received. The default is to not try the next server, which is the reverse of normal stub resolver behavior.

+[no]header-only

This option sends a query with a DNS header without a question section. The default is to add a question section. The query type and query name are ignored when this is set.

+[no]identify

This option shows [or does not show] the IP address and port number that supplied the answer, when the +short option is enabled. If short form answers are requested, the default is not to show the source address and port number of the server that provided the answer.

+[no]idnin

This option processes [or does not process] IDN domain names on input. This requires IDN SUPPORT to have been enabled at compile time.

The default is to process IDN input when standard output is a tty. The IDN processing on input is disabled when dig output is redirected to files, pipes, and other non-tty file descriptors.

+[no]idnout

This option converts [or does not convert] puny code on output. This requires IDN SUPPORT to have been enabled at compile time.

The default is to process puny code on output when standard output is a tty. The puny code processing on output is disabled when dig output is redirected to files, pipes, and other non-tty file descriptors.

+[no]ignore

This option ignores [or does not ignore] truncation in UDP responses instead of retrying with TCP. By default, TCP retries are performed.

+[no]keepalive

This option sends [or does not send] an EDNS Keepalive option.

+[no]keepopen

This option keeps [or does not keep] the TCP socket open between queries, and reuses it rather than creating a new TCP socket for each lookup. The default is +nokeepopen.

+[no]mapped

This option allows [or does not allow] mapped IPv4-over-IPv6 addresses to be used. The default is +mapped.

+[no]multiline

This option prints [or does not print] records, like the SOA records, in a verbose multi-line format with human-readable comments. The default is to print each record on a single line to facilitate machine parsing of the dig output.

+ndots=D

This option sets the number of dots (D) that must appear in name for it to be considered absolute. The default value is that defined using the ndots statement in /etc/resolv.conf, or 1 if no ndots statement is present. Names with fewer dots are interpreted as relative names, and are searched for in the domains listed in the search or domain directive in /etc/resolv.conf if +search is set.

+[no]nsid

When enabled, this option includes an EDNS name server ID request when sending a query.

+[no]nssearch

When this option is set, dig attempts to find the authoritative name servers for the zone containing the name being looked up, and display the SOA record that each name server has for the zone. Addresses of servers that did not respond are also printed.

+[no]onesoa

When enabled, this option prints only one (starting) SOA record when performing an AXFR. The default is to print both the starting and ending SOA records.

+[no]opcode=value

When enabled, this option sets (restores) the DNS message opcode to the specified value. The default value is QUERY (0).

+padding=value

This option pads the size of the query packet using the EDNS Padding option to blocks of value bytes. For example, +padding=32 causes a 48-byte query to be padded to 64 bytes. The default block size is 0, which disables padding; the maximum is 512. Values are ordinarily expected to be powers of two, such as 128; however, this is not mandatory. Responses to padded queries may also be padded, but only if the query uses TCP or DNS COOKIE.

+[no]qr

This option toggles the display of the query message as it is sent. By default, the query is not printed.

+[no]question

This option toggles the display of the question section of a query when an answer is returned. The default is to print the question section as a comment.

+[no]raflag

This option sets [or does not set] the RA (Recursion Available) bit in the query. The default is +noraflag. This bit is ignored by the server for QUERY.

+[no]rdflag

This option is a synonym for +[no]recurse.

+[no]recurse

This option toggles the setting of the RD (recursion desired) bit in the query. This bit is set by default, which means dig normally sends recursive queries. Recursion is automatically disabled when the +nssearch or +trace query option is used.

+retry=T

This option sets the number of times to retry UDP and TCP queries to server to T instead of the default, 2. Unlike +tries, this does not include the initial query.

+[no]rrcomments

This option toggles the display of per-record comments in the output (for example, human-readable key information about DNSKEY records). The default is not to print record comments unless multiline mode is active.

+[no]search

This option uses [or does not use] the search list defined by the searchlist or domain directive in resolv.conf, if any. The search list is not used by default.

ndots from resolv.conf (default 1), which may be overridden by +ndots, determines whether the name is treated as relative and hence whether a search is eventually performed.

+[no]short

This option toggles whether a terse answer is provided. The default is to print the answer in a verbose form. This option always has a global effect; it cannot be set globally and then overridden on a per-lookup basis.

+[no]showsearch

This option performs [or does not perform] a search showing intermediate results.

+[no]sigchase

This feature is now obsolete and has been removed; use delv instead.

+split=W

This option splits long hex- or base64-formatted fields in resource records into chunks of W characters (where W is rounded up to the nearest multiple of 4). +nosplit or +split=0 causes fields not to be split at all. The default is 56 characters, or 44 characters when multiline mode is active.

+[no]stats

This option toggles the printing of statistics: when the query was made, the size of the reply, etc. The default behavior is to print the query statistics as a comment after each lookup.

+[no]subnet=addr[/prefix-length]

This option sends [or does not send] an EDNS CLIENT-SUBNET option with the specified IP address or network prefix.

dig +subnet=0.0.0.0/0, or simply dig +subnet=0 for short, sends an EDNS CLIENT-SUBNET option with an empty address and a source prefix-length of zero, which signals a resolver that the client’s address information must not be used when resolving this query.

+[no]tcflag

This option sets [or does not set] the TC (TrunCation) bit in the query. The default is +notcflag. This bit is ignored by the server for QUERY.

+[no]tcp

This option uses [or does not use] TCP when querying name servers. The default behavior is to use UDP unless a type any or ixfr=N query is requested, in which case the default is TCP. AXFR queries always use TCP.

+timeout=T

This option sets the timeout for a query to T seconds. The default timeout is 5 seconds. An attempt to set T to less than 1 is silently set to 1.

+[no]topdown

This feature is related to dig +sigchase, which is obsolete and has been removed. Use delv instead.

+[no]trace

This option toggles tracing of the delegation path from the root name servers for the name being looked up. Tracing is disabled by default. When tracing is enabled, dig makes iterative queries to resolve the name being looked up. It follows referrals from the root servers, showing the answer from each server that was used to resolve the lookup.

If @server is also specified, it affects only the initial query for the root zone name servers.

+dnssec is also set when +trace is set, to better emulate the default queries from a name server.

+tries=T

This option sets the number of times to try UDP and TCP queries to server to T instead of the default, 3. If T is less than or equal to zero, the number of tries is silently rounded up to 1.

+trusted-key=####

This option formerly specified trusted keys for use with dig +sigchase. This feature is now obsolete and has been removed; use delv instead.

+[no]ttlid

This option displays [or does not display] the TTL when printing the record.

+[no]ttlunits

This option displays [or does not display] the TTL in friendly human-readable time units of s, m, h, d, and w, representing seconds, minutes, hours, days, and weeks. This implies +ttlid.

+[no]unexpected

This option accepts [or does not accept] answers from unexpected sources. By default, dig will not accept a reply from a source other than the one to which it sent the query.

+[no]unknownformat

This option prints all RDATA in unknown RR type presentation format (RFC 3597). The default is to print RDATA for known types in the type’s presentation format.

+[no]vc

This option uses [or does not use] TCP when querying name servers. This alternate syntax to +[no]tcp is provided for backwards compatibility. The vc stands for “virtual circuit.”

+[no]yaml

When enabled, this option prints the responses (and, if +qr is in use, also the outgoing queries) in a detailed YAML format.

+[no]zflag

This option sets [or does not set] the last unassigned DNS header flag in a DNS query. This flag is off by default.

Multiple Queries¶

The BIND 9 implementation of dig supports specifying multiple queries on the command line (in addition to supporting the -f batch file option). Each of those queries can be supplied with its own set of flags, options, and query options.

In this case, each query argument represents an individual query in the command-line syntax described above. Each consists of any of the standard options and flags, the name to be looked up, an optional query type and class, and any query options that should be applied to that query.

A global set of query options, which should be applied to all queries, can also be supplied. These global query options must precede the first tuple of name, class, type, options, flags, and query options supplied on the command line. Any global query options (except +[no]cmd and +[no]short options) can be overridden by a query-specific set of query options. For example:

dig +qr www.isc.org any -x 127.0.0.1 isc.org ns +noqr

shows how dig can be used from the command line to make three lookups: an ANY query for www.isc.org, a reverse lookup of 127.0.0.1, and a query for the NS records of isc.org. A global query option of +qr is applied, so that dig shows the initial query it made for each lookup. The final query has a local query option of +noqr which means that dig does not print the initial query when it looks up the NS records for isc.org.

IDN Support¶

If dig has been built with IDN (internationalized domain name) support, it can accept and display non-ASCII domain names. dig appropriately converts character encoding of a domain name before sending a request to a DNS server or displaying a reply from the server. To turn off IDN support, use the parameters +noidnin and +noidnout, or define the IDN_DISABLE environment variable.

Return Codes¶

dig return codes are:

0: DNS response received, including NXDOMAIN status
1: Usage error
8: Couldn’t open batch file
9: No reply from server
10: Internal error

Files¶

/etc/resolv.conf

${HOME}/.digrc

Bugs¶

There are probably too many query options.

dnssec-cds - change DS records for a child zone based on CDS/CDNSKEY¶

Synopsis¶

dnssec-cds [-a alg…] [-c class] [-D] {-d dsset-file} {-f child-file} [-i**[extension]] [-s** start-time] [-T ttl] [-u] [-v level] [-V] {domain}

Description¶

The dnssec-cds command changes DS records at a delegation point based on CDS or CDNSKEY records published in the child zone. If both CDS and CDNSKEY records are present in the child zone, the CDS is preferred. This enables a child zone to inform its parent of upcoming changes to its key-signing keys (KSKs); by polling periodically with dnssec-cds, the parent can keep the DS records up-to-date and enable automatic rolling of KSKs.

Two input files are required. The -f child-file option specifies a file containing the child’s CDS and/or CDNSKEY records, plus RRSIG and DNSKEY records so that they can be authenticated. The -d path option specifies the location of a file containing the current DS records. For example, this could be a dsset- file generated by dnssec-signzone, or the output of dnssec-dsfromkey, or the output of a previous run of dnssec-cds.

The dnssec-cds command uses special DNSSEC validation logic specified by RFC 7344. It requires that the CDS and/or CDNSKEY records be validly signed by a key represented in the existing DS records. This is typically the pre-existing KSK.

For protection against replay attacks, the signatures on the child records must not be older than they were on a previous run of dnssec-cds. Their age is obtained from the modification time of the dsset- file, or from the -s option.

To protect against breaking the delegation, dnssec-cds ensures that the DNSKEY RRset can be verified by every key algorithm in the new DS RRset, and that the same set of keys are covered by every DS digest type.

By default, replacement DS records are written to the standard output; with the -i option the input file is overwritten in place. The replacement DS records are the same as the existing records, when no change is required. The output can be empty if the CDS/CDNSKEY records specify that the child zone wants to be insecure.

Warning

Be careful not to delete the DS records when dnssec-cds fails!

Alternatively, dnssec-cds -u writes an nsupdate script to the standard output. The -u and -i options can be used together to maintain a dsset- file as well as emit an nsupdate script.

Options¶

-a algorithm

This option specifies a digest algorithm to use when converting CDNSKEY records to DS records. This option can be repeated, so that multiple DS records are created for each CDNSKEY record. This option has no effect when using CDS records.

The algorithm must be one of SHA-1, SHA-256, or SHA-384. These values are case-insensitive, and the hyphen may be omitted. If no algorithm is specified, the default is SHA-256.

-c class

This option specifies the DNS class of the zones.

-D

This option generates DS records from CDNSKEY records if both CDS and CDNSKEY records are present in the child zone. By default CDS records are preferred.

-d path

This specifies the location of the parent DS records. The path can be the name of a file containing the DS records; if it is a directory, dnssec-cds looks for a dsset- file for the domain inside the directory.

To protect against replay attacks, child records are rejected if they were signed earlier than the modification time of the dsset- file. This can be adjusted with the -s option.

-f child-file

This option specifies the file containing the child’s CDS and/or CDNSKEY records, plus its DNSKEY records and the covering RRSIG records, so that they can be authenticated.

The examples below describe how to generate this file.

-iextension

This option updates the dsset- file in place, instead of writing DS records to the standard output.

There must be no space between the -i and the extension. If no extension is provided, the old dsset- is discarded. If an extension is present, a backup of the old dsset- file is kept with the extension appended to its filename.

To protect against replay attacks, the modification time of the dsset- file is set to match the signature inception time of the child records, provided that it is later than the file’s current modification time.

-s start-time

This option specifies the date and time after which RRSIG records become acceptable. This can be either an absolute or a relative time. An absolute start time is indicated by a number in YYYYMMDDHHMMSS notation; 20170827133700 denotes 13:37:00 UTC on August 27th, 2017. A time relative to the dsset- file is indicated with -N, which is N seconds before the file modification time. A time relative to the current time is indicated with now+N.

If no start-time is specified, the modification time of the dsset- file is used.

-T ttl

This option specifies a TTL to be used for new DS records. If not specified, the default is the TTL of the old DS records. If they had no explicit TTL, the new DS records also have no explicit TTL.

-u

This option writes an nsupdate script to the standard output, instead of printing the new DS reords. The output is empty if no change is needed.

Note: The TTL of new records needs to be specified: it can be done in the original dsset- file, with the -T option, or using the nsupdate ttl command.

-V

This option prints version information.

-v level

This option sets the debugging level. Level 1 is intended to be usefully verbose for general users; higher levels are intended for developers.

domain

This indicates the name of the delegation point/child zone apex.

Exit Status¶

The dnssec-cds command exits 0 on success, or non-zero if an error occurred.

If successful, the DS records may or may not need to be changed.

Examples¶

Before running dnssec-signzone, ensure that the delegations are up-to-date by running dnssec-cds on every dsset- file.

To fetch the child records required by dnssec-cds, invoke dig as in the script below. It is acceptable if the dig fails, since dnssec-cds performs all the necessary checking.

for f in dsset-*
do
    d=${f#dsset-}
    dig +dnssec +noall +answer $d DNSKEY $d CDNSKEY $d CDS |
    dnssec-cds -i -f /dev/stdin -d $f $d
done

When the parent zone is automatically signed by named, dnssec-cds can be used with nsupdate to maintain a delegation as follows. The dsset- file allows the script to avoid having to fetch and validate the parent DS records, and it maintains the replay attack protection time.

dig +dnssec +noall +answer $d DNSKEY $d CDNSKEY $d CDS |
dnssec-cds -u -i -f /dev/stdin -d $f $d |
nsupdate -l

dnssec-dsfromkey - DNSSEC DS RR generation tool¶

Synopsis¶

dnssec-dsfromkey [ -1 | -2 | -a alg ] [ -C ] [-T TTL] [-v level] [-K directory] {keyfile}

dnssec-dsfromkey [ -1 | -2 | -a alg ] [ -C ] [-T TTL] [-v level] [-c class] [-A] {-f file} [dnsname]

dnssec-dsfromkey [ -1 | -2 | -a alg ] [ -C ] [-T TTL] [-v level] [-c class] [-K directory] {-s} {dnsname}

dnssec-dsfromkey [ -h | -V ]

Description¶

The dnssec-dsfromkey command outputs DS (Delegation Signer) resource records (RRs), or CDS (Child DS) RRs with the -C option.

The input keys can be specified in a number of ways:

By default, dnssec-dsfromkey reads a key file named in the format Knnnn.+aaa+iiiii.key, as generated by dnssec-keygen.

With the -f file option, dnssec-dsfromkey reads keys from a zone file or partial zone file (which can contain just the DNSKEY records).

With the -s option, dnssec-dsfromkey reads a keyset- file, as generated by dnssec-keygen -C.

Options¶

-1

This option is an abbreviation for -a SHA1.

-2

This option is an abbreviation for -a SHA-256.

-a algorithm

This option specifies a digest algorithm to use when converting DNSKEY records to DS records. This option can be repeated, so that multiple DS records are created for each DNSKEY record.

The algorithm must be one of SHA-1, SHA-256, or SHA-384. These values are case-insensitive, and the hyphen may be omitted. If no algorithm is specified, the default is SHA-256.

-A

This option indicates that ZSKs are to be included when generating DS records. Without this option, only keys which have the KSK flag set are converted to DS records and printed. This option is only useful in -f zone file mode.

-c class

This option specifies the DNS class; the default is IN. This option is only useful in -s keyset or -f zone file mode.

-C

This option generates CDS records rather than DS records.

-f file

This option sets zone file mode, in which the final dnsname argument of dnssec-dsfromkey is the DNS domain name of a zone whose master file can be read from file. If the zone name is the same as file, then it may be omitted.

If file is -, then the zone data is read from the standard input. This makes it possible to use the output of the dig command as input, as in:

dig dnskey example.com | dnssec-dsfromkey -f - example.com

-h

This option prints usage information.

-K directory

This option tells BIND 9 to look for key files or keyset- files in directory.

-s

This option enables keyset mode, in which the final dnsname argument from dnssec-dsfromkey is the DNS domain name used to locate a keyset- file.

-T TTL

This option specifies the TTL of the DS records. By default the TTL is omitted.

-v level

This option sets the debugging level.

-V

This option prints version information.

Example¶

To build the SHA-256 DS RR from the Kexample.com.+003+26160 keyfile, issue the following command:

dnssec-dsfromkey -2 Kexample.com.+003+26160

The command returns something similar to:

example.com. IN DS 26160 5 2 3A1EADA7A74B8D0BA86726B0C227AA85AB8BBD2B2004F41A868A54F0C5EA0B94

Files¶

The keyfile can be designated by the key identification Knnnn.+aaa+iiiii or the full file name Knnnn.+aaa+iiiii.key, as generated by dnssec-keygen.

The keyset file name is built from the directory, the string keyset-, and the dnsname.

Caveat¶

A keyfile error may return “file not found,” even if the file exists.

dnssec-importkey - import DNSKEY records from external systems so they can be managed¶

Synopsis¶

dnssec-importkey [-K directory] [-L ttl] [-P date/offset] [-P sync date/offset] [-D date/offset] [-D sync date/offset] [-h] [-v level] [-V] {keyfile}

dnssec-importkey {-f filename} [-K directory] [-L ttl] [-P date/offset] [-P sync date/offset] [-D date/offset] [-D sync date/offset] [-h] [-v level] [-V] [dnsname]

Description¶

dnssec-importkey reads a public DNSKEY record and generates a pair of .key/.private files. The DNSKEY record may be read from an existing .key file, in which case a corresponding .private file is generated, or it may be read from any other file or from the standard input, in which case both .key and .private files are generated.

The newly created .private file does not contain private key data, and cannot be used for signing. However, having a .private file makes it possible to set publication (-P) and deletion (-D) times for the key, which means the public key can be added to and removed from the DNSKEY RRset on schedule even if the true private key is stored offline.

Options¶

-f filename

This option indicates the zone file mode. Instead of a public keyfile name, the argument is the DNS domain name of a zone master file, which can be read from filename. If the domain name is the same as filename, then it may be omitted.

If filename is set to "-", then the zone data is read from the standard input.

-K directory

This option sets the directory in which the key files are to reside.

-L ttl

This option sets the default TTL to use for this key when it is converted into a DNSKEY RR. This is the TTL used when the key is imported into a zone, unless there was already a DNSKEY RRset in place, in which case the existing TTL takes precedence. Setting the default TTL to 0 or none removes it from the key.

-h

This option emits a usage message and exits.

-v level

This option sets the debugging level.

-V

This option prints version information.

Timing Options¶

Dates can be expressed in the format YYYYMMDD or YYYYMMDDHHMMSS. If the argument begins with a + or -, it is interpreted as an offset from the present time. For convenience, if such an offset is followed by one of the suffixes y, mo, w, d, h, or mi, then the offset is computed in years (defined as 365 24-hour days, ignoring leap years), months (defined as 30 24-hour days), weeks, days, hours, or minutes, respectively. Without a suffix, the offset is computed in seconds. To explicitly prevent a date from being set, use none or never.

-P date/offset: This option sets the date on which a key is to be published to the zone. After that date, the key is included in the zone but is not used to sign it.
-P sync date/offset: This option sets the date on which CDS and CDNSKEY records that match this key are to be published to the zone.
-D date/offset: This option sets the date on which the key is to be deleted. After that date, the key is no longer included in the zone. (However, it may remain in the key repository.)
-D sync date/offset: This option sets the date on which the CDS and CDNSKEY records that match this key are to be deleted.

Files¶

A keyfile can be designed by the key identification Knnnn.+aaa+iiiii or the full file name Knnnn.+aaa+iiiii.key, as generated by dnssec-keygen.

dnssec-checkds - DNSSEC delegation consistency checking tool¶

Synopsis¶

dnssec-checkds [-ddig path] [-Ddsfromkey path] [-ffile] [-ldomain] [-sfile] {zone}

Description¶

dnssec-checkds verifies the correctness of Delegation Signer (DS) resource records for keys in a specified zone.

Options¶

-a algorithm

Specify a digest algorithm to use when converting the zones DNSKEY records to expected DS records. This option can be repeated, so that multiple records are checked for each DNSKEY record.

The algorithm must be one of SHA-1, SHA-256, or SHA-384. These values are case insensitive, and the hyphen may be omitted. If no algorithm is specified, the default is SHA-256.

-f file

If a file is specified, then the zone is read from that file to find the DNSKEY records. If not, then the DNSKEY records for the zone are looked up in the DNS.

-s file

Specifies a prepared dsset file, such as would be generated by dnssec-signzone, to use as a source for the DS RRset instead of querying the parent.

-d dig path

Specifies a path to a dig binary. Used for testing.

-D dsfromkey path

Specifies a path to a dnssec-dsfromkey binary. Used for testing.

dnssec-coverage - checks future DNSKEY coverage for a zone¶

Synopsis¶

dnssec-coverage [-Kdirectory] [-llength] [-ffile] [-dDNSKEY TTL] [-mmax TTL] [-rinterval] [-ccompilezone path] [-k] [-z] [zone…]

Description¶

dnssec-coverage verifies that the DNSSEC keys for a given zone or a set of zones have timing metadata set properly to ensure no future lapses in DNSSEC coverage.

If zone is specified, then keys found in the key repository matching that zone are scanned, and an ordered list is generated of the events scheduled for that key (i.e., publication, activation, inactivation, deletion). The list of events is walked in order of occurrence. Warnings are generated if any event is scheduled which could cause the zone to enter a state in which validation failures might occur: for example, if the number of published or active keys for a given algorithm drops to zero, or if a key is deleted from the zone too soon after a new key is rolled, and cached data signed by the prior key has not had time to expire from resolver caches.

If zone is not specified, then all keys in the key repository will be scanned, and all zones for which there are keys will be analyzed. (Note: This method of reporting is only accurate if all the zones that have keys in a given repository share the same TTL parameters.)

Options¶

-K directory

Sets the directory in which keys can be found. Defaults to the current working directory.

-f file

If a file is specified, then the zone is read from that file; the largest TTL and the DNSKEY TTL are determined directly from the zone data, and the -m and -d options do not need to be specified on the command line.

-l duration

The length of time to check for DNSSEC coverage. Key events scheduled further into the future than duration will be ignored, and assumed to be correct.

The value of duration can be set in seconds, or in larger units of time by adding a suffix: mi for minutes, h for hours, d for days, w for weeks, mo for months, y for years.

-m maximum TTL

Sets the value to be used as the maximum TTL for the zone or zones being analyzed when determining whether there is a possibility of validation failure. When a zone-signing key is deactivated, there must be enough time for the record in the zone with the longest TTL to have expired from resolver caches before that key can be purged from the DNSKEY RRset. If that condition does not apply, a warning will be generated.

The length of the TTL can be set in seconds, or in larger units of time by adding a suffix: mi for minutes, h for hours, d for days, w for weeks, mo for months, y for years.

This option is not necessary if the -f has been used to specify a zone file. If -f has been specified, this option may still be used; it will override the value found in the file.

If this option is not used and the maximum TTL cannot be retrieved from a zone file, a warning is generated and a default value of 1 week is used.

-d DNSKEY TTL

Sets the value to be used as the DNSKEY TTL for the zone or zones being analyzed when determining whether there is a possibility of validation failure. When a key is rolled (that is, replaced with a new key), there must be enough time for the old DNSKEY RRset to have expired from resolver caches before the new key is activated and begins generating signatures. If that condition does not apply, a warning will be generated.

The length of the TTL can be set in seconds, or in larger units of time by adding a suffix: mi for minutes, h for hours, d for days, w for weeks, mo for months, y for years.

This option is not necessary if -f has been used to specify a zone file from which the TTL of the DNSKEY RRset can be read, or if a default key TTL was set using ith the -L to dnssec-keygen. If either of those is true, this option may still be used; it will override the values found in the zone file or the key file.

If this option is not used and the key TTL cannot be retrieved from the zone file or the key file, then a warning is generated and a default value of 1 day is used.

-r resign interval

Sets the value to be used as the resign interval for the zone or zones being analyzed when determining whether there is a possibility of validation failure. This value defaults to 22.5 days, which is also the default in named. However, if it has been changed by the sig-validity-interval option in named.conf, then it should also be changed here.

The length of the interval can be set in seconds, or in larger units of time by adding a suffix: mi for minutes, h for hours, d for days, w for weeks, mo for months, y for years.

-k

Only check KSK coverage; ignore ZSK events. Cannot be used with -z.

-z

Only check ZSK coverage; ignore KSK events. Cannot be used with -k.

-c compilezone path

Specifies a path to a named-compilezone binary. Used for testing.

dnssec-keymgr - Ensures correct DNSKEY coverage based on a defined policy¶

Synopsis¶

dnssec-keymgr [-Kdirectory] [-cfile] [-f] [-k] [-q] [-v] [-z] [-gpath] [-spath] [zone…]

Description¶

dnssec-keymgr is a high level Python wrapper to facilitate the key rollover process for zones handled by BIND. It uses the BIND commands for manipulating DNSSEC key metadata: dnssec-keygen and dnssec-settime.

DNSSEC policy can be read from a configuration file (default /etc/dnssec-policy.conf), from which the key parameters, publication and rollover schedule, and desired coverage duration for any given zone can be determined. This file may be used to define individual DNSSEC policies on a per-zone basis, or to set a “default” policy used for all zones.

When dnssec-keymgr runs, it examines the DNSSEC keys for one or more zones, comparing their timing metadata against the policies for those zones. If key settings do not conform to the DNSSEC policy (for example, because the policy has been changed), they are automatically corrected.

A zone policy can specify a duration for which we want to ensure the key correctness (coverage). It can also specify a rollover period (roll-period). If policy indicates that a key should roll over before the coverage period ends, then a successor key will automatically be created and added to the end of the key series.

If zones are specified on the command line, dnssec-keymgr will examine only those zones. If a specified zone does not already have keys in place, then keys will be generated for it according to policy.

If zones are not specified on the command line, then dnssec-keymgr will search the key directory (either the current working directory or the directory set by the -K option), and check the keys for all the zones represented in the directory.

Key times that are in the past will not be updated unless the -f is used (see below). Key inactivation and deletion times that are less than five minutes in the future will be delayed by five minutes.

It is expected that this tool will be run automatically and unattended (for example, by cron).

Options¶

-c file

If -c is specified, then the DNSSEC policy is read from file. (If not specified, then the policy is read from /etc/dnssec-policy.conf; if that file doesnt exist, a built-in global default policy is used.)

-f

Force: allow updating of key events even if they are already in the past. This is not recommended for use with zones in which keys have already been published. However, if a set of keys has been generated all of which have publication and activation dates in the past, but the keys have not been published in a zone as yet, then this option can be used to clean them up and turn them into a proper series of keys with appropriate rollover intervals.

-g keygen-path

Specifies a path to a dnssec-keygen binary. Used for testing. See also the -s option.

-h

Print the dnssec-keymgr help summary and exit.

-K directory

Sets the directory in which keys can be found. Defaults to the current working directory.

-k

Only apply policies to KSK keys. See also the -z option.

-q

Quiet: suppress printing of dnssec-keygen and dnssec-settime.

-s settime-path

Specifies a path to a dnssec-settime binary. Used for testing. See also the -g option.

-v

Print the dnssec-keymgr version and exit.

-z

Only apply policies to ZSK keys. See also the -k option.

Policy Configuration¶

The dnssec-policy.conf file can specify three kinds of policies:

· Policy classes (policyname{ ... };) can be inherited by zone policies or other policy classes; these can be used to create sets of different security profiles. For example, a policy class normal might specify 1024-bit key sizes, but a class extra might specify 2048 bits instead; extra would be used for zones that had unusually high security needs.

· Algorithm policies: (algorithm-policyalgorithm{ ... }; ) override default per-algorithm settings. For example, by default, RSASHA256 keys use 2048-bit key sizes for both KSK and ZSK. This can be modified using algorithm-policy, and the new key sizes would then be used for any key of type RSASHA256.

· Zone policies: (zonename{ ... }; ) set policy for a single zone by name. A zone policy can inherit a policy class by including a policy option. Zone names beginning with digits (i.e., 0-9) must be quoted. If a zone does not have its own policy then the “default” policy applies.

Options that can be specified in policies:

algorithm name;

The key algorithm. If no policy is defined, the default is RSASHA256.

coverage duration;

The length of time to ensure that keys will be correct; no action will be taken to create new keys to be activated after this time. This can be represented as a number of seconds, or as a duration using human-readable units (examples: “1y” or “6 months”). A default value for this option can be set in algorithm policies as well as in policy classes or zone policies. If no policy is configured, the default is six months.

directory path;

Specifies the directory in which keys should be stored.

key-size keytype size;

Specifies the number of bits to use in creating keys. The keytype is either “zsk” or “ksk”. A default value for this option can be set in algorithm policies as well as in policy classes or zone policies. If no policy is configured, the default is 2048 bits for RSA keys.

keyttl duration;

The key TTL. If no policy is defined, the default is one hour.

post-publish keytype duration;

How long after inactivation a key should be deleted from the zone. Note: If roll-period is not set, this value is ignored. The keytype is either “zsk” or “ksk”. A default duration for this option can be set in algorithm policies as well as in policy classes or zone policies. The default is one month.

pre-publish keytype duration;

How long before activation a key should be published. Note: If roll-period is not set, this value is ignored. The keytype is either “zsk” or “ksk”. A default duration for this option can be set in algorithm policies as well as in policy classes or zone policies. The default is one month.

roll-period keytype duration;

How frequently keys should be rolled over. The keytype is either “zsk” or “ksk”. A default duration for this option can be set in algorithm policies as well as in policy classes or zone policies. If no policy is configured, the default is one year for ZSKs. KSKs do not roll over by default.

standby keytype number;

Not yet implemented.

Remaining Work¶

· Enable scheduling of KSK rollovers using the -P sync and -D sync options to dnssec-keygen and dnssec-settime. Check the parent zone (as in dnssec-checkds) to determine when its safe for the key to roll.

· Allow configuration of standby keys and use of the REVOKE bit, for keys that use RFC 5011 semantics.

dnssec-keyfromlabel - DNSSEC key generation tool¶

Synopsis¶

dnssec-keyfromlabel {-l label} [-3] [-a algorithm] [-A date/offset] [-c class] [-D date/offset] [-D sync date/offset] [-E engine] [-f flag] [-G] [-I date/offset] [-i interval] [-k] [-K directory] [-L ttl] [-n nametype] [-P date/offset] [-P sync date/offset] [-p protocol] [-R date/offset] [-S key] [-t type] [-v level] [-V] [-y] {name}

Description¶

dnssec-keyfromlabel generates a pair of key files that reference a key object stored in a cryptographic hardware service module (HSM). The private key file can be used for DNSSEC signing of zone data as if it were a conventional signing key created by dnssec-keygen, but the key material is stored within the HSM and the actual signing takes place there.

The name of the key is specified on the command line. This must match the name of the zone for which the key is being generated.

Options¶

-a algorithm

This option selects the cryptographic algorithm. The value of algorithm must be one of RSASHA1, NSEC3RSASHA1, RSASHA256, RSASHA512, ECDSAP256SHA256, ECDSAP384SHA384, ED25519, or ED448.

If no algorithm is specified, RSASHA1 is used by default unless the -3 option is specified, in which case NSEC3RSASHA1 is used instead. (If -3 is used and an algorithm is specified, that algorithm is checked for compatibility with NSEC3.)

These values are case-insensitive. In some cases, abbreviations are supported, such as ECDSA256 for ECDSAP256SHA256 and ECDSA384 for ECDSAP384SHA384. If RSASHA1 is specified along with the -3 option, then NSEC3RSASHA1 is used instead.

Since BIND 9.12.0, this option is mandatory except when using the -S option, which copies the algorithm from the predecessory key. Previously, the default for newly generated keys was RSASHA1.

-3

This option uses an NSEC3-capable algorithm to generate a DNSSEC key. If this option is used with an algorithm that has both NSEC and NSEC3 versions, then the NSEC3 version is used; for example, dnssec-keygen -3a RSASHA1 specifies the NSEC3RSASHA1 algorithm.

-E engine

This option specifies the cryptographic hardware to use.

When BIND 9 is built with OpenSSL, this needs to be set to the OpenSSL engine identifier that drives the cryptographic accelerator or hardware service module (usually pkcs11). When BIND is built with native PKCS#11 cryptography (--enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via --with-pkcs11.

-l label

This option specifies the label for a key pair in the crypto hardware.

When BIND 9 is built with OpenSSL-based PKCS#11 support, the label is an arbitrary string that identifies a particular key. It may be preceded by an optional OpenSSL engine name, followed by a colon, as in pkcs11:keylabel.

When BIND 9 is built with native PKCS#11 support, the label is a PKCS#11 URI string in the format pkcs11:keyword\ =value[;\ keyword\ =value;...]. Keywords include token, which identifies the HSM; object, which identifies the key; and pin-source, which identifies a file from which the HSM’s PIN code can be obtained. The label is stored in the on-disk private file.

If the label contains a pin-source field, tools using the generated key files are able to use the HSM for signing and other operations without any need for an operator to manually enter a PIN. Note: Making the HSM’s PIN accessible in this manner may reduce the security advantage of using an HSM; use caution with this feature.

-n nametype

This option specifies the owner type of the key. The value of nametype must either be ZONE (for a DNSSEC zone key (KEY/DNSKEY)), HOST or ENTITY (for a key associated with a host (KEY)), USER (for a key associated with a user (KEY)), or OTHER (DNSKEY). These values are case-insensitive.

-C

This option enables compatibility mode, which generates an old-style key, without any metadata. By default, dnssec-keyfromlabel includes the key’s creation date in the metadata stored with the private key; other dates may be set there as well, including publication date, activation date, etc. Keys that include this data may be incompatible with older versions of BIND; the -C option suppresses them.

-c class

This option indicates that the DNS record containing the key should have the specified class. If not specified, class IN is used.

-f flag

This option sets the specified flag in the flag field of the KEY/DNSKEY record. The only recognized flags are KSK (Key-Signing Key) and REVOKE.

-G

This option generates a key, but does not publish it or sign with it. This option is incompatible with -P and -A.

-h

This option prints a short summary of the options and arguments to dnssec-keyfromlabel.

-K directory

This option sets the directory in which the key files are to be written.

-k

This option generates KEY records rather than DNSKEY records.

-L ttl

This option sets the default TTL to use for this key when it is converted into a DNSKEY RR. This is the TTL used when the key is imported into a zone, unless there was already a DNSKEY RRset in place, in which case the existing TTL would take precedence. Setting the default TTL to 0 or none removes it.

-p protocol

This option sets the protocol value for the key. The protocol is a number between 0 and 255. The default is 3 (DNSSEC). Other possible values for this argument are listed in RFC 2535 and its successors.

-S key

This option generates a key as an explicit successor to an existing key. The name, algorithm, size, and type of the key are set to match the predecessor. The activation date of the new key is set to the inactivation date of the existing one. The publication date is set to the activation date minus the prepublication interval, which defaults to 30 days.

-t type

This option indicates the type of the key. type must be one of AUTHCONF, NOAUTHCONF, NOAUTH, or NOCONF. The default is AUTHCONF. AUTH refers to the ability to authenticate data, and CONF to the ability to encrypt data.

-v level

This option sets the debugging level.

-V

This option prints version information.

-y

This option allows DNSSEC key files to be generated even if the key ID would collide with that of an existing key, in the event of either key being revoked. (This is only safe to enable if RFC 5011 trust anchor maintenance is not used with either of the keys involved.)

Timing Options¶

Dates can be expressed in the format YYYYMMDD or YYYYMMDDHHMMSS. If the argument begins with a + or -, it is interpreted as an offset from the present time. For convenience, if such an offset is followed by one of the suffixes y, mo, w, d, h, or mi, then the offset is computed in years (defined as 365 24-hour days, ignoring leap years), months (defined as 30 24-hour days), weeks, days, hours, or minutes, respectively. Without a suffix, the offset is computed in seconds. To explicitly prevent a date from being set, use none or never.

-P date/offset

This option sets the date on which a key is to be published to the zone. After that date, the key is included in the zone but is not used to sign it. If not set, and if the -G option has not been used, the default is the current date.

-P sync date/offset

This option sets the date on which CDS and CDNSKEY records that match this key are to be published to the zone.

-A date/offset

This option sets the date on which the key is to be activated. After that date, the key is included in the zone and used to sign it. If not set, and if the -G option has not been used, the default is the current date.

-R date/offset

This option sets the date on which the key is to be revoked. After that date, the key is flagged as revoked. It is included in the zone and is used to sign it.

-I date/offset

This option sets the date on which the key is to be retired. After that date, the key is still included in the zone, but it is not used to sign it.

-D date/offset

This option sets the date on which the key is to be deleted. After that date, the key is no longer included in the zone. (However, it may remain in the key repository.)

-D sync date/offset

This option sets the date on which the CDS and CDNSKEY records that match this key are to be deleted.

-i interval

This option sets the prepublication interval for a key. If set, then the publication and activation dates must be separated by at least this much time. If the activation date is specified but the publication date is not, the publication date defaults to this much time before the activation date; conversely, if the publication date is specified but not the activation date, activation is set to this much time after publication.

If the key is being created as an explicit successor to another key, then the default prepublication interval is 30 days; otherwise it is zero.

As with date offsets, if the argument is followed by one of the suffixes y, mo, w, d, h, or mi, the interval is measured in years, months, weeks, days, hours, or minutes, respectively. Without a suffix, the interval is measured in seconds.

Generated Key Files¶

When dnssec-keyfromlabel completes successfully, it prints a string of the form Knnnn.+aaa+iiiii to the standard output. This is an identification string for the key files it has generated.

nnnn is the key name.
aaa is the numeric representation of the algorithm.
iiiii is the key identifier (or footprint).

dnssec-keyfromlabel creates two files, with names based on the printed string. Knnnn.+aaa+iiiii.key contains the public key, and Knnnn.+aaa+iiiii.private contains the private key.

The .key file contains a DNS KEY record that can be inserted into a zone file (directly or with an $INCLUDE statement).

The .private file contains algorithm-specific fields. For obvious security reasons, this file does not have general read permission.

dnssec-keygen: DNSSEC key generation tool¶

Synopsis¶

dnssec-keygen [-3] [-A date/offset] [-a algorithm] [-b keysize] [-C] [-c class] [-D date/offset] [-d bits] [-D sync date/offset] [-E engine] [-f flag] [-G] [-g generator] [-h] [-I date/offset] [-i interval] [-K directory] [-k policy] [-L ttl] [-l file] [-n nametype] [-P date/offset] [-P sync date/offset] [-p protocol] [-q] [-R date/offset] [-S key] [-s strength] [-T rrtype] [-t type] [-V] [-v level] {name}

Description¶

dnssec-keygen generates keys for DNSSEC (Secure DNS), as defined in RFC 2535 and RFC 4034. It can also generate keys for use with TSIG (Transaction Signatures) as defined in RFC 2845, or TKEY (Transaction Key) as defined in RFC 2930.

The name of the key is specified on the command line. For DNSSEC keys, this must match the name of the zone for which the key is being generated.

The dnssec-keymgr command acts as a wrapper around dnssec-keygen, generating and updating keys as needed to enforce defined security policies such as key rollover scheduling. Using dnssec-keymgr may be preferable to direct use of dnssec-keygen.

Options¶

-3

This option uses an NSEC3-capable algorithm to generate a DNSSEC key. If this option is used with an algorithm that has both NSEC and NSEC3 versions, then the NSEC3 version is selected; for example, dnssec-keygen -3a RSASHA1 specifies the NSEC3RSASHA1 algorithm.

-a algorithm

This option selects the cryptographic algorithm. For DNSSEC keys, the value of algorithm must be one of RSASHA1, NSEC3RSASHA1, RSASHA256, RSASHA512, ECDSAP256SHA256, ECDSAP384SHA384, ED25519, or ED448. For TKEY, the value must be DH (Diffie-Hellman); specifying this value automatically sets the -T KEY option as well.

These values are case-insensitive. In some cases, abbreviations are supported, such as ECDSA256 for ECDSAP256SHA256 and ECDSA384 for ECDSAP384SHA384. If RSASHA1 is specified along with the -3 option, NSEC3RSASHA1 is used instead.

This parameter must be specified except when using the -S option, which copies the algorithm from the predecessor key.

In prior releases, HMAC algorithms could be generated for use as TSIG keys, but that feature was removed in BIND 9.13.0. Use tsig-keygen to generate TSIG keys.

-b keysize

This option specifies the number of bits in the key. The choice of key size depends on the algorithm used: RSA keys must be between 1024 and 4096 bits; Diffie-Hellman keys must be between 128 and 4096 bits. Elliptic curve algorithms do not need this parameter.

If the key size is not specified, some algorithms have pre-defined defaults. For example, RSA keys for use as DNSSEC zone-signing keys have a default size of 1024 bits; RSA keys for use as key-signing keys (KSKs, generated with -f KSK) default to 2048 bits.

-C

This option enables compatibility mode, which generates an old-style key, without any timing metadata. By default, dnssec-keygen includes the key’s creation date in the metadata stored with the private key; other dates may be set there as well, including publication date, activation date, etc. Keys that include this data may be incompatible with older versions of BIND; the -C option suppresses them.

-c class

This option indicates that the DNS record containing the key should have the specified class. If not specified, class IN is used.

-d bits

This option specifies the key size in bits. For the algorithms RSASHA1, NSEC3RSASA1, RSASHA256, and RSASHA512 the key size must be between 1024 and 4096 bits; DH size is between 128 and 4096 bits. This option is ignored for algorithms ECDSAP256SHA256, ECDSAP384SHA384, ED25519, and ED448.

-E engine

This option specifies the cryptographic hardware to use, when applicable.

When BIND 9 is built with OpenSSL, this needs to be set to the OpenSSL engine identifier that drives the cryptographic accelerator or hardware service module (usually pkcs11). When BIND is built with native PKCS#11 cryptography (--enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via --with-pkcs11.

-f flag

This option sets the specified flag in the flag field of the KEY/DNSKEY record. The only recognized flags are KSK (Key-Signing Key) and REVOKE.

-G

This option generates a key, but does not publish it or sign with it. This option is incompatible with -P and -A.

-g generator

This option indicates the generator to use if generating a Diffie-Hellman key. Allowed values are 2 and 5. If no generator is specified, a known prime from RFC 2539 is used if possible; otherwise the default is 2.

-h

This option prints a short summary of the options and arguments to dnssec-keygen.

-K directory

This option sets the directory in which the key files are to be written.

-k policy

This option creates keys for a specific dnssec-policy. If a policy uses multiple keys, dnssec-keygen generates multiple keys. This also creates a “.state” file to keep track of the key state.

This option creates keys according to the dnssec-policy configuration, hence it cannot be used at the same time as many of the other options that dnssec-keygen provides.

-L ttl

This option sets the default TTL to use for this key when it is converted into a DNSKEY RR. This is the TTL used when the key is imported into a zone, unless there was already a DNSKEY RRset in place, in which case the existing TTL takes precedence. If this value is not set and there is no existing DNSKEY RRset, the TTL defaults to the SOA TTL. Setting the default TTL to 0 or none is the same as leaving it unset.

-l file

This option provides a configuration file that contains a dnssec-policy statement (matching the policy set with -k).

-n nametype

This option specifies the owner type of the key. The value of nametype must either be ZONE (for a DNSSEC zone key (KEY/DNSKEY)), HOST or ENTITY (for a key associated with a host (KEY)), USER (for a key associated with a user (KEY)), or OTHER (DNSKEY). These values are case-insensitive. The default is ZONE for DNSKEY generation.

-p protocol

This option sets the protocol value for the generated key, for use with -T KEY. The protocol is a number between 0 and 255. The default is 3 (DNSSEC). Other possible values for this argument are listed in RFC 2535 and its successors.

-q

This option sets quiet mode, which suppresses unnecessary output, including progress indication. Without this option, when dnssec-keygen is run interactively to generate an RSA or DSA key pair, it prints a string of symbols to stderr indicating the progress of the key generation. A . indicates that a random number has been found which passed an initial sieve test; + means a number has passed a single round of the Miller-Rabin primality test; and a space ( ) means that the number has passed all the tests and is a satisfactory key.

-S key

This option creates a new key which is an explicit successor to an existing key. The name, algorithm, size, and type of the key are set to match the existing key. The activation date of the new key is set to the inactivation date of the existing one. The publication date is set to the activation date minus the prepublication interval, which defaults to 30 days.

-s strength

This option specifies the strength value of the key. The strength is a number between 0 and 15, and currently has no defined purpose in DNSSEC.

-T rrtype

This option specifies the resource record type to use for the key. rrtype must be either DNSKEY or KEY. The default is DNSKEY when using a DNSSEC algorithm, but it can be overridden to KEY for use with SIG(0).

-t type

This option indicates the type of the key for use with -T KEY. type must be one of AUTHCONF, NOAUTHCONF, NOAUTH, or NOCONF. The default is AUTHCONF. AUTH refers to the ability to authenticate data, and CONF to the ability to encrypt data.

-V

This option prints version information.

-v level

This option sets the debugging level.

Timing Options¶

Dates can be expressed in the format YYYYMMDD or YYYYMMDDHHMMSS. If the argument begins with a + or -, it is interpreted as an offset from the present time. For convenience, if such an offset is followed by one of the suffixes y, mo, w, d, h, or mi, then the offset is computed in years (defined as 365 24-hour days, ignoring leap years), months (defined as 30 24-hour days), weeks, days, hours, or minutes, respectively. Without a suffix, the offset is computed in seconds. To explicitly prevent a date from being set, use none or never.

-P date/offset

This option sets the date on which a key is to be published to the zone. After that date, the key is included in the zone but is not used to sign it. If not set, and if the -G option has not been used, the default is the current date.

-P sync date/offset

This option sets the date on which CDS and CDNSKEY records that match this key are to be published to the zone.

-A date/offset

This option sets the date on which the key is to be activated. After that date, the key is included in the zone and used to sign it. If not set, and if the -G option has not been used, the default is the current date. If set, and -P is not set, the publication date is set to the activation date minus the prepublication interval.

-R date/offset

This option sets the date on which the key is to be revoked. After that date, the key is flagged as revoked. It is included in the zone and is used to sign it.

-I date/offset

This option sets the date on which the key is to be retired. After that date, the key is still included in the zone, but it is not used to sign it.

-D date/offset

This option sets the date on which the key is to be deleted. After that date, the key is no longer included in the zone. (However, it may remain in the key repository.)

-D sync date/offset

This option sets the date on which the CDS and CDNSKEY records that match this key are to be deleted.

-i interval

This option sets the prepublication interval for a key. If set, then the publication and activation dates must be separated by at least this much time. If the activation date is specified but the publication date is not, the publication date defaults to this much time before the activation date; conversely, if the publication date is specified but not the activation date, activation is set to this much time after publication.

If the key is being created as an explicit successor to another key, then the default prepublication interval is 30 days; otherwise it is zero.

As with date offsets, if the argument is followed by one of the suffixes y, mo, w, d, h, or mi, the interval is measured in years, months, weeks, days, hours, or minutes, respectively. Without a suffix, the interval is measured in seconds.

Generated Keys¶

When dnssec-keygen completes successfully, it prints a string of the form Knnnn.+aaa+iiiii to the standard output. This is an identification string for the key it has generated.

nnnn is the key name.
aaa is the numeric representation of the algorithm.
iiiii is the key identifier (or footprint).

dnssec-keygen creates two files, with names based on the printed string. Knnnn.+aaa+iiiii.key contains the public key, and Knnnn.+aaa+iiiii.private contains the private key.

The .key file contains a DNSKEY or KEY record. When a zone is being signed by named or dnssec-signzone -S, DNSKEY records are included automatically. In other cases, the .key file can be inserted into a zone file manually or with an $INCLUDE statement.

The .private file contains algorithm-specific fields. For obvious security reasons, this file does not have general read permission.

Example¶

To generate an ECDSAP256SHA256 zone-signing key for the zone example.com, issue the command:

dnssec-keygen -a ECDSAP256SHA256 example.com

The command prints a string of the form:

Kexample.com.+013+26160

In this example, dnssec-keygen creates the files Kexample.com.+013+26160.key and Kexample.com.+013+26160.private.

To generate a matching key-signing key, issue the command:

dnssec-keygen -a ECDSAP256SHA256 -f KSK example.com

dnssec-revoke - set the REVOKED bit on a DNSSEC key¶

Synopsis¶

dnssec-revoke [-hr] [-v level] [-V] [-K directory] [-E engine] [-f] [-R] {keyfile}

Description¶

dnssec-revoke reads a DNSSEC key file, sets the REVOKED bit on the key as defined in RFC 5011, and creates a new pair of key files containing the now-revoked key.

Options¶

-h

This option emits a usage message and exits.

-K directory

This option sets the directory in which the key files are to reside.

-r

This option indicates to remove the original keyset files after writing the new keyset files.

-v level

This option sets the debugging level.

-V

This option prints version information.

-E engine

This option specifies the cryptographic hardware to use, when applicable.

When BIND 9 is built with OpenSSL, this needs to be set to the OpenSSL engine identifier that drives the cryptographic accelerator or hardware service module (usually pkcs11). When BIND is built with native PKCS#11 cryptography (--enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via --with-pkcs11.

-f

This option indicates a forced overwrite and causes dnssec-revoke to write the new key pair, even if a file already exists matching the algorithm and key ID of the revoked key.

-R

This option prints the key tag of the key with the REVOKE bit set, but does not revoke the key.

dnssec-settime: set the key timing metadata for a DNSSEC key¶

Synopsis¶

dnssec-settime [-f] [-K directory] [-L ttl] [-P date/offset] [-P ds date/offset] [-P sync date/offset] [-A date/offset] [-R date/offset] [-I date/offset] [-D date/offset] [-D ds date/offset] [-D sync date/offset] [-S key] [-i interval] [-h] [-V] [-v level] [-E engine] {keyfile} [-s] [-g state] [-d state date/offset] [-k state date/offset] [-r state date/offset] [-z state date/offset]

Description¶

dnssec-settime reads a DNSSEC private key file and sets the key timing metadata as specified by the -P, -A, -R, -I, and -D options. The metadata can then be used by dnssec-signzone or other signing software to determine when a key is to be published, whether it should be used for signing a zone, etc.

If none of these options is set on the command line, dnssec-settime simply prints the key timing metadata already stored in the key.

When key metadata fields are changed, both files of a key pair (Knnnn.+aaa+iiiii.key and Knnnn.+aaa+iiiii.private) are regenerated.

Metadata fields are stored in the private file. A human-readable description of the metadata is also placed in comments in the key file. The private file’s permissions are always set to be inaccessible to anyone other than the owner (mode 0600).

When working with state files, it is possible to update the timing metadata in those files as well with -s. With this option, it is also possible to update key states with -d (DS), -k (DNSKEY), -r (RRSIG of KSK), or -z (RRSIG of ZSK). Allowed states are HIDDEN, RUMOURED, OMNIPRESENT, and UNRETENTIVE.

The goal state of the key can also be set with -g. This should be either HIDDEN or OMNIPRESENT, representing whether the key should be removed from the zone or published.

It is NOT RECOMMENDED to manipulate state files manually, except for testing purposes.

Options¶

-f

This option forces an update of an old-format key with no metadata fields. Without this option, dnssec-settime fails when attempting to update a legacy key. With this option, the key is recreated in the new format, but with the original key data retained. The key’s creation date is set to the present time. If no other values are specified, then the key’s publication and activation dates are also set to the present time.

-K directory

This option sets the directory in which the key files are to reside.

-L ttl

This option sets the default TTL to use for this key when it is converted into a DNSKEY RR. This is the TTL used when the key is imported into a zone, unless there was already a DNSKEY RRset in place, in which case the existing TTL takes precedence. If this value is not set and there is no existing DNSKEY RRset, the TTL defaults to the SOA TTL. Setting the default TTL to 0 or none removes it from the key.

-h

This option emits a usage message and exits.

-V

This option prints version information.

-v level

This option sets the debugging level.

-E engine

This option specifies the cryptographic hardware to use, when applicable.

When BIND 9 is built with OpenSSL, this needs to be set to the OpenSSL engine identifier that drives the cryptographic accelerator or hardware service module (usually pkcs11). When BIND is built with native PKCS#11 cryptography (--enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via --with-pkcs11.

Timing Options¶

Dates can be expressed in the format YYYYMMDD or YYYYMMDDHHMMSS. If the argument begins with a + or -, it is interpreted as an offset from the present time. For convenience, if such an offset is followed by one of the suffixes y, mo, w, d, h, or mi, then the offset is computed in years (defined as 365 24-hour days, ignoring leap years), months (defined as 30 24-hour days), weeks, days, hours, or minutes, respectively. Without a suffix, the offset is computed in seconds. To explicitly prevent a date from being set, use none or never.

-P date/offset

This option sets the date on which a key is to be published to the zone. After that date, the key is included in the zone but is not used to sign it.

-P ds date/offset

This option Sets the date on which DS records that match this key have been seen in the parent zone.

-P sync date/offset

This option sets the date on which CDS and CDNSKEY records that match this key are to be published to the zone.

-A date/offset

This option sets the date on which the key is to be activated. After that date, the key is included in the zone and used to sign it.

-R date/offset

This option sets the date on which the key is to be revoked. After that date, the key is flagged as revoked. It is included in the zone and is used to sign it.

-I date/offset

This option sets the date on which the key is to be retired. After that date, the key is still included in the zone, but it is not used to sign it.

-D date/offset

This option sets the date on which the key is to be deleted. After that date, the key is no longer included in the zone. (However, it may remain in the key repository.)

-D ds date/offset

This option sets the date on which the DS records that match this key have been seen removed from the parent zone.

-D sync date/offset

This option sets the date on which the CDS and CDNSKEY records that match this key are to be deleted.

-S predecessor key

This option selects a key for which the key being modified is an explicit successor. The name, algorithm, size, and type of the predecessor key must exactly match those of the key being modified. The activation date of the successor key is set to the inactivation date of the predecessor. The publication date is set to the activation date minus the prepublication interval, which defaults to 30 days.

-i interval

This option sets the prepublication interval for a key. If set, then the publication and activation dates must be separated by at least this much time. If the activation date is specified but the publication date is not, the publication date defaults to this much time before the activation date; conversely, if the publication date is specified but not the activation date, activation is set to this much time after publication.

If the key is being created as an explicit successor to another key, then the default prepublication interval is 30 days; otherwise it is zero.

As with date offsets, if the argument is followed by one of the suffixes y, mo, w, d, h, or mi, the interval is measured in years, months, weeks, days, hours, or minutes, respectively. Without a suffix, the interval is measured in seconds.

Key State Options¶

To test dnssec-policy it may be necessary to construct keys with artificial state information; these options are used by the testing framework for that purpose, but should never be used in production.

Known key states are HIDDEN, RUMOURED, OMNIPRESENT, and UNRETENTIVE.

-s: This option indicates that when setting key timing data, the state file should also be updated.
-g state: This option sets the goal state for this key. Must be HIDDEN or OMNIPRESENT.
-d state date/offset: This option sets the DS state for this key as of the specified date, offset from the current date.
-k state date/offset: This option sets the DNSKEY state for this key as of the specified date, offset from the current date.
-r state date/offset: This option sets the RRSIG (KSK) state for this key as of the specified date, offset from the current date.
-z state date/offset: This option sets the RRSIG (ZSK) state for this key as of the specified date, offset from the current date.

Printing Options¶

dnssec-settime can also be used to print the timing metadata associated with a key.

-u: This option indicates that times should be printed in Unix epoch format.
-p C/P/Pds/Psync/A/R/I/D/Dds/Dsync/all: This option prints a specific metadata value or set of metadata values. The -p option may be followed by one or more of the following letters or strings to indicate which value or values to print: C for the creation date, P for the publication date, Pds` for the DS publication date, ``Psync for the CDS and CDNSKEY publication date, A for the activation date, R for the revocation date, I for the inactivation date, D for the deletion date, Dds for the DS deletion date, and Dsync for the CDS and CDNSKEY deletion date. To print all of the metadata, use all.

dnssec-signzone - DNSSEC zone signing tool¶

Synopsis¶

dnssec-signzone [-a] [-c class] [-d directory] [-D] [-E engine] [-e end-time] [-f output-file] [-g] [-h] [-i interval] [-I input-format] [-j jitter] [-K directory] [-k key] [-L serial] [-M maxttl] [-N soa-serial-format] [-o origin] [-O output-format] [-P] [-Q] [-q] [-R] [-S] [-s start-time] [-T ttl] [-t] [-u] [-v level] [-V] [-X extended end-time] [-x] [-z] [-3 salt] [-H iterations] [-A] {zonefile} [key…]

Description¶

dnssec-signzone signs a zone; it generates NSEC and RRSIG records and produces a signed version of the zone. The security status of delegations from the signed zone (that is, whether the child zones are secure) is determined by the presence or absence of a keyset file for each child zone.

Options¶

-a

This option verifies all generated signatures.

-c class

This option specifies the DNS class of the zone.

-C

This option sets compatibility mode, in which a keyset-zonename file is generated in addition to dsset-zonename when signing a zone, for use by older versions of dnssec-signzone.

-d directory

This option indicates the directory where BIND 9 should look for dsset- or keyset- files.

-D

This option indicates that only those record types automatically managed by dnssec-signzone, i.e., RRSIG, NSEC, NSEC3 and NSEC3PARAM records, should be included in the output. If smart signing (-S) is used, DNSKEY records are also included. The resulting file can be included in the original zone file with $INCLUDE. This option cannot be combined with -O raw, -O map, or serial-number updating.

-E engine

This option specifies the hardware to use for cryptographic operations, such as a secure key store used for signing, when applicable.

When BIND 9 is built with OpenSSL, this needs to be set to the OpenSSL engine identifier that drives the cryptographic accelerator or hardware service module (usually pkcs11). When BIND is built with native PKCS#11 cryptography (--enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via --with-pkcs11.

-g

This option indicates that DS records for child zones should be generated from a dsset- or keyset- file. Existing DS records are removed.

-K directory

This option specifies the directory to search for DNSSEC keys. If not specified, it defaults to the current directory.

-k key

This option tells BIND 9 to treat the specified key as a key-signing key, ignoring any key flags. This option may be specified multiple times.

-M maxttl

This option sets the maximum TTL for the signed zone. Any TTL higher than maxttl in the input zone is reduced to maxttl in the output. This provides certainty as to the largest possible TTL in the signed zone, which is useful to know when rolling keys. The maxttl is the longest possible time before signatures that have been retrieved by resolvers expire from resolver caches. Zones that are signed with this option should be configured to use a matching max-zone-ttl in named.conf. (Note: This option is incompatible with -D, because it modifies non-DNSSEC data in the output zone.)

-s start-time

This option specifies the date and time when the generated RRSIG records become valid. This can be either an absolute or relative time. An absolute start time is indicated by a number in YYYYMMDDHHMMSS notation; 20000530144500 denotes 14:45:00 UTC on May 30th, 2000. A relative start time is indicated by +N, which is N seconds from the current time. If no start-time is specified, the current time minus 1 hour (to allow for clock skew) is used.

-e end-time

This option specifies the date and time when the generated RRSIG records expire. As with start-time, an absolute time is indicated in YYYYMMDDHHMMSS notation. A time relative to the start time is indicated with +N, which is N seconds from the start time. A time relative to the current time is indicated with now+N. If no end-time is specified, 30 days from the start time is the default. end-time must be later than start-time.

-X extended end-time

This option specifies the date and time when the generated RRSIG records for the DNSKEY RRset expire. This is to be used in cases when the DNSKEY signatures need to persist longer than signatures on other records; e.g., when the private component of the KSK is kept offline and the KSK signature is to be refreshed manually.

As with end-time, an absolute time is indicated in YYYYMMDDHHMMSS notation. A time relative to the start time is indicated with +N, which is N seconds from the start time. A time relative to the current time is indicated with now+N. If no extended end-time is specified, the value of end-time is used as the default. (end-time, in turn, defaults to 30 days from the start time.) extended end-time must be later than start-time.

-f output-file

This option indicates the name of the output file containing the signed zone. The default is to append .signed to the input filename. If output-file is set to -, then the signed zone is written to the standard output, with a default output format of full.

-h

This option prints a short summary of the options and arguments to dnssec-signzone.

-V

This option prints version information.

-i interval

This option indicates that, when a previously signed zone is passed as input, records may be re-signed. The interval option specifies the cycle interval as an offset from the current time, in seconds. If a RRSIG record expires after the cycle interval, it is retained; otherwise, it is considered to be expiring soon and it is replaced.

The default cycle interval is one quarter of the difference between the signature end and start times. So if neither end-time nor start-time is specified, dnssec-signzone generates signatures that are valid for 30 days, with a cycle interval of 7.5 days. Therefore, if any existing RRSIG records are due to expire in less than 7.5 days, they are replaced.

-I input-format

This option sets the format of the input zone file. Possible formats are text (the default), raw, and map. This option is primarily intended to be used for dynamic signed zones, so that the dumped zone file in a non-text format containing updates can be signed directly. This option is not useful for non-dynamic zones.

-j jitter

When signing a zone with a fixed signature lifetime, all RRSIG records issued at the time of signing expire simultaneously. If the zone is incrementally signed, i.e., a previously signed zone is passed as input to the signer, all expired signatures must be regenerated at approximately the same time. The jitter option specifies a jitter window that is used to randomize the signature expire time, thus spreading incremental signature regeneration over time.

Signature lifetime jitter also, to some extent, benefits validators and servers by spreading out cache expiration, i.e., if large numbers of RRSIGs do not expire at the same time from all caches, there is less congestion than if all validators need to refetch at around the same time.

-L serial

When writing a signed zone to “raw” or “map” format, this option sets the “source serial” value in the header to the specified serial number. (This is expected to be used primarily for testing purposes.)

-n ncpus

This option specifies the number of threads to use. By default, one thread is started for each detected CPU.

-N soa-serial-format

This option sets the SOA serial number format of the signed zone. Possible formats are keep (the default), increment, unixtime, and date.

keep: This format indicates that the SOA serial number should not be modified.
increment: This format increments the SOA serial number using RFC 1982 arithmetic.
unixtime: This format sets the SOA serial number to the number of seconds since the beginning of the Unix epoch, unless the serial number is already greater than or equal to that value, in which case it is simply incremented by one.
date: This format sets the SOA serial number to today’s date, in YYYYMMDDNN format, unless the serial number is already greater than or equal to that value, in which case it is simply incremented by one.

-o origin

This option sets the zone origin. If not specified, the name of the zone file is assumed to be the origin.

-O output-format

This option sets the format of the output file containing the signed zone. Possible formats are text (the default), which is the standard textual representation of the zone; full, which is text output in a format suitable for processing by external scripts; and map, raw, and raw=N, which store the zone in binary formats for rapid loading by named. raw=N specifies the format version of the raw zone file: if N is 0, the raw file can be read by any version of named; if N is 1, the file can be read by release 9.9.0 or higher. The default is 1.

-P

This option disables post-sign verification tests.

The post-sign verification tests ensure that for each algorithm in use there is at least one non-revoked self-signed KSK key, that all revoked KSK keys are self-signed, and that all records in the zone are signed by the algorithm. This option skips these tests.

-Q

This option removes signatures from keys that are no longer active.

Normally, when a previously signed zone is passed as input to the signer, and a DNSKEY record has been removed and replaced with a new one, signatures from the old key that are still within their validity period are retained. This allows the zone to continue to validate with cached copies of the old DNSKEY RRset. The -Q option forces dnssec-signzone to remove signatures from keys that are no longer active. This enables ZSK rollover using the procedure described in RFC 4641#4.2.1.1 (“Pre-Publish Key Rollover”).

-q

This option enables quiet mode, which suppresses unnecessary output. Without this option, when dnssec-signzone is run it prints three pieces of information to standard output: the number of keys in use; the algorithms used to verify the zone was signed correctly and other status information; and the filename containing the signed zone. With the option that output is suppressed, leaving only the filename.

-R

This option removes signatures from keys that are no longer published.

This option is similar to -Q, except it forces dnssec-signzone to remove signatures from keys that are no longer published. This enables ZSK rollover using the procedure described in RFC 4641#4.2.1.2 (“Double Signature Zone Signing Key Rollover”).

-S

This option enables smart signing, which instructs dnssec-signzone to search the key repository for keys that match the zone being signed, and to include them in the zone if appropriate.

When a key is found, its timing metadata is examined to determine how it should be used, according to the following rules. Each successive rule takes priority over the prior ones:

If no timing metadata has been set for the key, the key is published in the zone and used to sign the zone.

If the key’s publication date is set and is in the past, the key is published in the zone.

If the key’s activation date is set and is in the past, the key is published (regardless of publication date) and used to sign the zone.

If the key’s revocation date is set and is in the past, and the key is published, then the key is revoked, and the revoked key is used to sign the zone.

If either the key’s unpublication or deletion date is set and in the past, the key is NOT published or used to sign the zone, regardless of any other metadata.

If the key’s sync publication date is set and is in the past, synchronization records (type CDS and/or CDNSKEY) are created.

If the key’s sync deletion date is set and is in the past, synchronization records (type CDS and/or CDNSKEY) are removed.

-T ttl

This option specifies a TTL to be used for new DNSKEY records imported into the zone from the key repository. If not specified, the default is the TTL value from the zone’s SOA record. This option is ignored when signing without -S, since DNSKEY records are not imported from the key repository in that case. It is also ignored if there are any pre-existing DNSKEY records at the zone apex, in which case new records’ TTL values are set to match them, or if any of the imported DNSKEY records had a default TTL value. In the event of a conflict between TTL values in imported keys, the shortest one is used.

-t

This option prints statistics at completion.

-u

This option updates the NSEC/NSEC3 chain when re-signing a previously signed zone. With this option, a zone signed with NSEC can be switched to NSEC3, or a zone signed with NSEC3 can be switched to NSEC or to NSEC3 with different parameters. Without this option, dnssec-signzone retains the existing chain when re-signing.

-v level

This option sets the debugging level.

-x

This option indicates that BIND 9 should only sign the DNSKEY, CDNSKEY, and CDS RRsets with key-signing keys, and should omit signatures from zone-signing keys. (This is similar to the dnssec-dnskey-kskonly yes; zone option in named.)

-z

This option indicates that BIND 9 should ignore the KSK flag on keys when determining what to sign. This causes KSK-flagged keys to sign all records, not just the DNSKEY RRset. (This is similar to the update-check-ksk no; zone option in named.)

-3 salt

This option generates an NSEC3 chain with the given hex-encoded salt. A dash (-) can be used to indicate that no salt is to be used when generating the NSEC3 chain.

-H iterations

This option indicates that, when generating an NSEC3 chain, BIND 9 should use this many iterations. The default is 10.

-A

This option indicates that, when generating an NSEC3 chain, BIND 9 should set the OPTOUT flag on all NSEC3 records and should not generate NSEC3 records for insecure delegations.

Using this option twice (i.e., -AA) turns the OPTOUT flag off for all records. This is useful when using the -u option to modify an NSEC3 chain which previously had OPTOUT set.

zonefile

This option sets the file containing the zone to be signed.

key

This option specifies which keys should be used to sign the zone. If no keys are specified, the zone is examined for DNSKEY records at the zone apex. If these records are found and there are matching private keys in the current directory, they are used for signing.

Example¶

The following command signs the example.com zone with the ECDSAP256SHA256 key generated by dnssec-keygen (Kexample.com.+013+17247). Because the -S option is not being used, the zone’s keys must be in the master file (db.example.com). This invocation looks for dsset files in the current directory, so that DS records can be imported from them (-g).

% dnssec-signzone -g -o example.com db.example.com \
Kexample.com.+013+17247
db.example.com.signed
%

In the above example, dnssec-signzone creates the file db.example.com.signed. This file should be referenced in a zone statement in the named.conf file.

This example re-signs a previously signed zone with default parameters. The private keys are assumed to be in the current directory.

% cp db.example.com.signed db.example.com
% dnssec-signzone -o example.com db.example.com
db.example.com.signed
%

dnssec-verify - DNSSEC zone verification tool¶

Synopsis¶

dnssec-verify [-c class] [-E engine] [-I input-format] [-o origin] [-q] [-v level] [-V] [-x] [-z] {zonefile}

Description¶

dnssec-verify verifies that a zone is fully signed for each algorithm found in the DNSKEY RRset for the zone, and that the NSEC/NSEC3 chains are complete.

Options¶

-c class

This option specifies the DNS class of the zone.

-E engine

This option specifies the cryptographic hardware to use, when applicable.

When BIND 9 is built with OpenSSL, this needs to be set to the OpenSSL engine identifier that drives the cryptographic accelerator or hardware service module (usually pkcs11). When BIND is built with native PKCS#11 cryptography (--enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via --with-pkcs11.

-I input-format

This option sets the format of the input zone file. Possible formats are text (the default) and raw. This option is primarily intended to be used for dynamic signed zones, so that the dumped zone file in a non-text format containing updates can be verified independently. This option is not useful for non-dynamic zones.

-o origin

This option indicates the zone origin. If not specified, the name of the zone file is assumed to be the origin.

-v level

This option sets the debugging level.

-V

This option prints version information.

-q

This option sets quiet mode, which suppresses output. Without this option, when dnssec-verify is run it prints to standard output the number of keys in use, the algorithms used to verify the zone was signed correctly, and other status information. With this option, all non-error output is suppressed, and only the exit code indicates success.

-x

This option verifies only that the DNSKEY RRset is signed with key-signing keys. Without this flag, it is assumed that the DNSKEY RRset is signed by all active keys. When this flag is set, it is not an error if the DNSKEY RRset is not signed by zone-signing keys. This corresponds to the -x option in dnssec-signzone.

-z

This option indicates that the KSK flag on the keys should be ignored when determining whether the zone is correctly signed. Without this flag, it is assumed that there is a non-revoked, self-signed DNSKEY with the KSK flag set for each algorithm, and that RRsets other than DNSKEY RRset are signed with a different DNSKEY without the KSK flag set.

With this flag set, BIND 9 only requires that for each algorithm, there be at least one non-revoked, self-signed DNSKEY, regardless of the KSK flag state, and that other RRsets be signed by a non-revoked key for the same algorithm that includes the self-signed key; the same key may be used for both purposes. This corresponds to the -z option in dnssec-signzone.

zonefile

This option indicates the file containing the zone to be signed.

dnstap-read - print dnstap data in human-readable form¶

Synopsis¶

dnstap-read [-m] [-p] [-x] [-y] {file}

Description¶

dnstap-read reads dnstap data from a specified file and prints it in a human-readable format. By default, dnstap data is printed in a short summary format, but if the -y option is specified, a longer and more detailed YAML format is used.

Options¶

-m: This option indicates trace memory allocations, and is used for debugging memory leaks.
-p: This option prints the text form of the DNS message that was encapsulated in the dnstap frame, after printing the dnstap data.
-x: This option prints a hex dump of the wire form of the DNS message that was encapsulated in the dnstap frame, after printing the dnstap data.
-y: This option prints dnstap data in a detailed YAML format.

filter-aaaa.so - filter AAAA in DNS responses when A is present¶

Synopsis¶

plugin query “filter-aaaa.so” [{ parameters }];

Description¶

filter-aaaa.so is a query plugin module for named, enabling named to omit some IPv6 addresses when responding to clients.

Until BIND 9.12, this feature was implemented natively in named and enabled with the filter-aaaa ACL and the filter-aaaa-on-v4 and filter-aaaa-on-v6 options. These options are now deprecated in named.conf but can be passed as parameters to the filter-aaaa.so plugin, for example:

plugin query "/usr/local/lib/filter-aaaa.so" {
        filter-aaaa-on-v4 yes;
        filter-aaaa-on-v6 yes;
        filter-aaaa { 192.0.2.1; 2001:db8:2::1; };
};

This module is intended to aid transition from IPv4 to IPv6 by withholding IPv6 addresses from DNS clients which are not connected to the IPv6 Internet, when the name being looked up has an IPv4 address available. Use of this module is not recommended unless absolutely necessary.

Note: This mechanism can erroneously cause other servers not to give AAAA records to their clients. If a recursing server with both IPv6 and IPv4 network connections queries an authoritative server using this mechanism via IPv4, it is denied AAAA records even if its client is using IPv6.

Options¶

filter-aaaa

This option specifies a list of client addresses for which AAAA filtering is to be applied. The default is any.

filter-aaaa-on-v4

If set to yes, this option indicates that the DNS client is at an IPv4 address, in filter-aaaa. If the response does not include DNSSEC signatures, then all AAAA records are deleted from the response. This filtering applies to all responses, not only authoritative ones.

If set to break-dnssec, then AAAA records are deleted even when DNSSEC is enabled. As suggested by the name, this causes the response to fail to verify, because the DNSSEC protocol is designed to detect deletions.

This mechanism can erroneously cause other servers not to give AAAA records to their clients. If a recursing server with both IPv6 and IPv4 network connections queries an authoritative server using this mechanism via IPv4, it is denied AAAA records even if its client is using IPv6.

filter-aaaa-on-v6

This option is identical to filter-aaaa-on-v4, except that it filters AAAA responses to queries from IPv6 clients instead of IPv4 clients. To filter all responses, set both options to yes.

host - DNS lookup utility¶

Synopsis¶

host [-aACdlnrsTUwv] [-c class] [-N ndots] [-p port] [-R number] [-t type] [-W wait] [-m flag] [ [-4] | [-6] ] [-v] [-V] {name} [server]

Description¶

host is a simple utility for performing DNS lookups. It is normally used to convert names to IP addresses and vice versa. When no arguments or options are given, host prints a short summary of its command-line arguments and options.

name is the domain name that is to be looked up. It can also be a dotted-decimal IPv4 address or a colon-delimited IPv6 address, in which case host by default performs a reverse lookup for that address. server is an optional argument which is either the name or IP address of the name server that host should query instead of the server or servers listed in /etc/resolv.conf.

Options¶

-4

This option specifies that only IPv4 should be used for query transport. See also the -6 option.

-6

This option specifies that only IPv6 should be used for query transport. See also the -4 option.

-a

The -a (“all”) option is normally equivalent to -v -t ANY. It also affects the behavior of the -l list zone option.

-A

The -A (“almost all”) option is equivalent to -a, except that RRSIG, NSEC, and NSEC3 records are omitted from the output.

-c class

This option specifies the query class, which can be used to lookup HS (Hesiod) or CH (Chaosnet) class resource records. The default class is IN (Internet).

-C

This option indicates that named should check consistency, meaning that host queries the SOA records for zone name from all the listed authoritative name servers for that zone. The list of name servers is defined by the NS records that are found for the zone.

-d

This option prints debugging traces, and is equivalent to the -v verbose option.

-l

This option tells named` to list the zone, meaning the ``host command performs a zone transfer of zone name and prints out the NS, PTR, and address records (A/AAAA).

Together, the -l -a options print all records in the zone.

-N ndots

This option specifies the number of dots (ndots) that have to be in name for it to be considered absolute. The default value is that defined using the ndots statement in /etc/resolv.conf, or 1 if no ndots statement is present. Names with fewer dots are interpreted as relative names, and are searched for in the domains listed in the search or domain directive in /etc/resolv.conf.

-p port

This option specifies the port to query on the server. The default is 53.

-r

This option specifies a non-recursive query; setting this option clears the RD (recursion desired) bit in the query. This means that the name server receiving the query does not attempt to resolve name. The -r option enables host to mimic the behavior of a name server by making non-recursive queries, and expecting to receive answers to those queries that can be referrals to other name servers.

-R number

This option specifies the number of retries for UDP queries. If number is negative or zero, the number of retries is silently set to 1. The default value is 1, or the value of the attempts option in /etc/resolv.conf, if set.

-s

This option tells named not to send the query to the next nameserver if any server responds with a SERVFAIL response, which is the reverse of normal stub resolver behavior.

-t type

This option specifies the query type. The type argument can be any recognized query type: CNAME, NS, SOA, TXT, DNSKEY, AXFR, etc.

When no query type is specified, host automatically selects an appropriate query type. By default, it looks for A, AAAA, and MX records. If the -C option is given, queries are made for SOA records. If name is a dotted-decimal IPv4 address or colon-delimited IPv6 address, host queries for PTR records.

If a query type of IXFR is chosen, the starting serial number can be specified by appending an equals sign (=), followed by the starting serial number, e.g., -t IXFR=12345678.

-T; -U

This option specifies TCP or UDP. By default, host uses UDP when making queries; the -T option makes it use a TCP connection when querying the name server. TCP is automatically selected for queries that require it, such as zone transfer (AXFR) requests. Type ANY queries default to TCP, but can be forced to use UDP initially via -U.

-m flag

This option sets memory usage debugging: the flag can be record, usage, or trace. The -m option can be specified more than once to set multiple flags.

-v

This option sets verbose output, and is equivalent to the -d debug option. Verbose output can also be enabled by setting the debug option in /etc/resolv.conf.

-V

This option prints the version number and exits.

-w

This option sets “wait forever”: the query timeout is set to the maximum possible. See also the -W option.

-W wait

This options sets the length of the wait timeout, indicating that named should wait for up to wait seconds for a reply. If wait is less than 1, the wait interval is set to 1 second.

By default, host waits for 5 seconds for UDP responses and 10 seconds for TCP connections. These defaults can be overridden by the timeout option in /etc/resolv.conf.

IDN Support¶

If host has been built with IDN (internationalized domain name) support, it can accept and display non-ASCII domain names. host appropriately converts character encoding of a domain name before sending a request to a DNS server or displaying a reply from the server. To turn off IDN support, define the IDN_DISABLE environment variable. IDN support is disabled if the variable is set when host runs.

Files¶

/etc/resolv.conf

mdig - DNS pipelined lookup utility¶

Synopsis¶

mdig {@server} [-f filename] [-h] [-v] [ [-4] | [-6] ] [-m] [-b address] [-p port#] [-c class] [-t type] [-i] [-x addr] [plusopt…]

mdig {-h}

mdig [@server] {global-opt…} { {local-opt…} {query} …}

Description¶

mdig is a multiple/pipelined query version of dig: instead of waiting for a response after sending each query, it begins by sending all queries. Responses are displayed in the order in which they are received, not in the order the corresponding queries were sent.

mdig options are a subset of the dig options, and are divided into “anywhere options,” which can occur anywhere, “global options,” which must occur before the query name (or they are ignored with a warning), and “local options,” which apply to the next query on the command line.

The @server option is a mandatory global option. It is the name or IP address of the name server to query. (Unlike dig, this value is not retrieved from /etc/resolv.conf.) It can be an IPv4 address in dotted-decimal notation, an IPv6 address in colon-delimited notation, or a hostname. When the supplied server argument is a hostname, mdig resolves that name before querying the name server.

mdig provides a number of query options which affect the way in which lookups are made and the results displayed. Some of these set or reset flag bits in the query header, some determine which sections of the answer get printed, and others determine the timeout and retry strategies.

Each query option is identified by a keyword preceded by a plus sign (+). Some keywords set or reset an option. These may be preceded by the string no to negate the meaning of that keyword. Other keywords assign values to options like the timeout interval. They have the form +keyword=value.

Anywhere Options¶

-f: This option makes mdig operate in batch mode by reading a list of lookup requests to process from the file filename. The file contains a number of queries, one per line. Each entry in the file should be organized in the same way they would be presented as queries to mdig using the command-line interface.
-h: This option causes mdig to print detailed help information, with the full list of options, and exit.
-v: This option causes mdig to print the version number and exit.

Global Options¶

-4: This option forces mdig to only use IPv4 query transport.
-6: This option forces mdig to only use IPv6 query transport.
-b address: This option sets the source IP address of the query to address. This must be a valid address on one of the host’s network interfaces or “0.0.0.0” or “::”. An optional port may be specified by appending “#<port>”
-m: This option enables memory usage debugging.
-p port#: This option is used when a non-standard port number is to be queried. port# is the port number that mdig sends its queries to, instead of the standard DNS port number 53. This option is used to test a name server that has been configured to listen for queries on a non-standard port number.

The global query options are:

+[no]additional: This option displays [or does not display] the additional section of a reply. The default is to display it.
+[no]all: This option sets or clears all display flags.
+[no]answer: This option displays [or does not display] the answer section of a reply. The default is to display it.
+[no]authority: This option displays [or does not display] the authority section of a reply. The default is to display it.
+[no]besteffort: This option attempts to display [or does not display] the contents of messages which are malformed. The default is to not display malformed answers.
+burst: This option delays queries until the start of the next second.
+[no]cl: This option displays [or does not display] the CLASS when printing the record.
+[no]comments: This option toggles the display of comment lines in the output. The default is to print comments.
+[no]continue: This option toggles continuation on errors (e.g. timeouts).
+[no]crypto: This option toggles the display of cryptographic fields in DNSSEC records. The contents of these fields are unnecessary to debug most DNSSEC validation failures and removing them makes it easier to see the common failures. The default is to display the fields. When omitted, they are replaced by the string “[omitted]”; in the DNSKEY case, the key ID is displayed as the replacement, e.g., [ key id = value ].
+dscp[=value]: This option sets the DSCP code point to be used when sending the query. Valid DSCP code points are in the range [0…63]. By default no code point is explicitly set.
+[no]multiline: This option toggles printing of records, like the SOA records, in a verbose multi-line format with human-readable comments. The default is to print each record on a single line, to facilitate machine parsing of the mdig output.
+[no]question: This option prints [or does not print] the question section of a query when an answer is returned. The default is to print the question section as a comment.
+[no]rrcomments: This option toggles the display of per-record comments in the output (for example, human-readable key information about DNSKEY records). The default is not to print record comments unless multiline mode is active.
+[no]short: This option provides [or does not provide] a terse answer. The default is to print the answer in a verbose form.
+split=W: This option splits long hex- or base64-formatted fields in resource records into chunks of W characters (where W is rounded up to the nearest multiple of 4). +nosplit or +split=0 causes fields not to be split. The default is 56 characters, or 44 characters when multiline mode is active.
+[no]tcp: This option uses [or does not use] TCP when querying name servers. The default behavior is to use UDP.
+[no]ttlid: This option displays [or does not display] the TTL when printing the record.
+[no]ttlunits: This option displays [or does not display] the TTL in friendly human-readable time units of “s”, “m”, “h”, “d”, and “w”, representing seconds, minutes, hours, days, and weeks. This implies +ttlid.
+[no]vc: This option uses [or does not use] TCP when querying name servers. This alternate syntax to +[no]tcp is provided for backwards compatibility. The vc stands for “virtual circuit”.

Local Options¶

-c class: This option sets the query class to class. It can be any valid query class which is supported in BIND 9. The default query class is “IN”.
-t type: This option sets the query type to type. It can be any valid query type which is supported in BIND 9. The default query type is “A”, unless the -x option is supplied to indicate a reverse lookup with the “PTR” query type.
-x addr: Reverse lookups - mapping addresses to names - are simplified by this option. addr is an IPv4 address in dotted-decimal notation, or a colon-delimited IPv6 address. mdig automatically performs a lookup for a query name like 11.12.13.10.in-addr.arpa and sets the query type and class to PTR and IN respectively. By default, IPv6 addresses are looked up using nibble format under the IP6.ARPA domain.

The local query options are:

+[no]aaflag: This is a synonym for +[no]aaonly.
+[no]aaonly: This sets the aa flag in the query.
+[no]adflag: This sets [or does not set] the AD (authentic data) bit in the query. This requests the server to return whether all of the answer and authority sections have all been validated as secure, according to the security policy of the server. AD=1 indicates that all records have been validated as secure and the answer is not from a OPT-OUT range. AD=0 indicates that some part of the answer was insecure or not validated. This bit is set by default.
+bufsize=B: This sets the UDP message buffer size advertised using EDNS0 to B bytes. The maximum and minimum sizes of this buffer are 65535 and 0 respectively. Values outside this range are rounded up or down appropriately. Values other than zero cause a EDNS query to be sent.
+[no]cdflag: This sets [or does not set] the CD (checking disabled) bit in the query. This requests the server to not perform DNSSEC validation of responses.
+[no]cookie=####: This sends [or does not send] a COOKIE EDNS option, with an optional value. Replaying a COOKIE from a previous response allows the server to identify a previous client. The default is +nocookie.
+[no]dnssec: This requests that DNSSEC records be sent by setting the DNSSEC OK (DO) bit in the OPT record in the additional section of the query.
+[no]edns[=#]: This specifies [or does not specify] the EDNS version to query with. Valid values are 0 to 255. Setting the EDNS version causes an EDNS query to be sent. +noedns clears the remembered EDNS version. EDNS is set to 0 by default.
+[no]ednsflags[=#]: This sets the must-be-zero EDNS flag bits (Z bits) to the specified value. Decimal, hex, and octal encodings are accepted. Setting a named flag (e.g. DO) is silently ignored. By default, no Z bits are set.
+[no]ednsopt[=code[:value]]: This specifies [or does not specify] an EDNS option with code point code and an optional payload of value as a hexadecimal string. +noednsopt clears the EDNS options to be sent.
+[no]expire: This toggles sending of an EDNS Expire option.
+[no]nsid: This toggles inclusion of an EDNS name server ID request when sending a query.
+[no]recurse: This toggles the setting of the RD (recursion desired) bit in the query. This bit is set by default, which means mdig normally sends recursive queries.
+retry=T: This sets the number of times to retry UDP queries to server to T instead of the default, 2. Unlike +tries, this does not include the initial query.
+[no]subnet=addr[/prefix-length]: This sends [or does not send] an EDNS Client Subnet option with the specified IP address or network prefix.
mdig +subnet=0.0.0.0/0, or simply mdig +subnet=0: This sends an EDNS client-subnet option with an empty address and a source prefix-length of zero, which signals a resolver that the client’s address information must not be used when resolving this query.
+timeout=T: This sets the timeout for a query to T seconds. The default timeout is 5 seconds for UDP transport and 10 for TCP. An attempt to set T to less than 1 results in a query timeout of 1 second being applied.
+tries=T: This sets the number of times to try UDP queries to server to T instead of the default, 3. If T is less than or equal to zero, the number of tries is silently rounded up to 1.
+udptimeout=T: This sets the timeout between UDP query retries to T.
+[no]unknownformat: This prints [or does not print] all RDATA in unknown RR-type presentation format (see RFC 3597). The default is to print RDATA for known types in the type’s presentation format.
+[no]yaml: This toggles printing of the responses in a detailed YAML format.
+[no]zflag: This sets [or does not set] the last unassigned DNS header flag in a DNS query. This flag is off by default.

named-checkconf - named configuration file syntax checking tool¶

Synopsis¶

named-checkconf [-chjlvz] [-p [-x ]] [-t directory] {filename}

Description¶

named-checkconf checks the syntax, but not the semantics, of a named configuration file. The file, along with all files included by it, is parsed and checked for syntax errors. If no file is specified, /etc/named.conf is read by default.

Note: files that named reads in separate parser contexts, such as rndc.key and bind.keys, are not automatically read by named-checkconf. Configuration errors in these files may cause named to fail to run, even if named-checkconf was successful. However, named-checkconf can be run on these files explicitly.

Options¶

-h: This option prints the usage summary and exits.
-j: When loading a zonefile, this option instructs named to read the journal if it exists.
-l: This option lists all the configured zones. Each line of output contains the zone name, class (e.g. IN), view, and type (e.g. primary or secondary).
-c: This option specifies that only the “core” configuration should be checked. This suppresses the loading of plugin modules, and causes all parameters to plugin statements to be ignored.
-i: This option ignores warnings on deprecated options.
-p: This option prints out the named.conf and included files in canonical form if no errors were detected. See also the -x option.
-t directory: This option instructs named to chroot to directory, so that include directives in the configuration file are processed as if run by a similarly chrooted named.
-v: This option prints the version of the named-checkconf program and exits.
-x: When printing the configuration files in canonical form, this option obscures shared secrets by replacing them with strings of question marks (?). This allows the contents of named.conf and related files to be shared - for example, when submitting bug reports - without compromising private data. This option cannot be used without -p.
-z: This option performs a test load of all zones of type primary found in named.conf.
filename: This indicates the name of the configuration file to be checked. If not specified, it defaults to /etc/named.conf.

Return Values¶

named-checkconf returns an exit status of 1 if errors were detected and 0 otherwise.

named-checkzone, named-compilezone - zone file validity checking or converting tool¶

Synopsis¶

named-checkzone [-d] [-h] [-j] [-q] [-v] [-c class] [-f format] [-F format] [-J filename] [-i mode] [-k mode] [-m mode] [-M mode] [-n mode] [-l ttl] [-L serial] [-o filename] [-r mode] [-s style] [-S mode] [-t directory] [-T mode] [-w directory] [-D] [-W mode] {zonename} {filename}

named-compilezone [-d] [-j] [-q] [-v] [-c class] [-C mode] [-f format] [-F format] [-J filename] [-i mode] [-k mode] [-m mode] [-n mode] [-l ttl] [-L serial] [-r mode] [-s style] [-t directory] [-T mode] [-w directory] [-D] [-W mode] {-o filename} {zonename} {filename}

Description¶

named-checkzone checks the syntax and integrity of a zone file. It performs the same checks as named does when loading a zone. This makes named-checkzone useful for checking zone files before configuring them into a name server.

named-compilezone is similar to named-checkzone, but it always dumps the zone contents to a specified file in a specified format. It also applies stricter check levels by default, since the dump output is used as an actual zone file loaded by named. When manually specified otherwise, the check levels must at least be as strict as those specified in the named configuration file.

Options¶

-d

This option enables debugging.

-h

This option prints the usage summary and exits.

-q

This option sets quiet mode, which only sets an exit code to indicate successful or failed completion.

-v

This option prints the version of the named-checkzone program and exits.

-j

When loading a zone file, this option tells named to read the journal if it exists. The journal file name is assumed to be the zone file name with the string .jnl appended.

-J filename

When loading the zone file, this option tells named to read the journal from the given file, if it exists. This implies -j.

-c class

This option specifies the class of the zone. If not specified, IN is assumed.

-i mode

This option performs post-load zone integrity checks. Possible modes are full (the default), full-sibling, local, local-sibling, and none.

Mode full checks that MX records refer to A or AAAA records (both in-zone and out-of-zone hostnames). Mode local only checks MX records which refer to in-zone hostnames.

Mode full checks that SRV records refer to A or AAAA records (both in-zone and out-of-zone hostnames). Mode local only checks SRV records which refer to in-zone hostnames.

Mode full checks that delegation NS records refer to A or AAAA records (both in-zone and out-of-zone hostnames). It also checks that glue address records in the zone match those advertised by the child. Mode local only checks NS records which refer to in-zone hostnames or verifies that some required glue exists, i.e., when the name server is in a child zone.

Modes full-sibling and local-sibling disable sibling glue checks, but are otherwise the same as full and local, respectively.

Mode none disables the checks.

-f format

This option specifies the format of the zone file. Possible formats are text (the default), raw, and map.

-F format

This option specifies the format of the output file specified. For named-checkzone, this does not have any effect unless it dumps the zone contents.

Possible formats are text (the default), which is the standard textual representation of the zone, and map, raw, and raw=N, which store the zone in a binary format for rapid loading by named. raw=N specifies the format version of the raw zone file: if N is 0, the raw file can be read by any version of named; if N is 1, the file can only be read by release 9.9.0 or higher. The default is 1.

-k mode

This option performs check-names checks with the specified failure mode. Possible modes are fail (the default for named-compilezone), warn (the default for named-checkzone), and ignore.

-l ttl

This option sets a maximum permissible TTL for the input file. Any record with a TTL higher than this value causes the zone to be rejected. This is similar to using the max-zone-ttl option in named.conf.

-L serial

When compiling a zone to raw or map format, this option sets the “source serial” value in the header to the specified serial number. This is expected to be used primarily for testing purposes.

-m mode

This option specifies whether MX records should be checked to see if they are addresses. Possible modes are fail, warn (the default), and ignore.

-M mode

This option checks whether a MX record refers to a CNAME. Possible modes are fail, warn (the default), and ignore.

-n mode

This option specifies whether NS records should be checked to see if they are addresses. Possible modes are fail (the default for named-compilezone), warn (the default for named-checkzone), and ignore.

-o filename

This option writes the zone output to filename. If filename is -, then the zone output is written to standard output. This is mandatory for named-compilezone.

-r mode

This option checks for records that are treated as different by DNSSEC but are semantically equal in plain DNS. Possible modes are fail, warn (the default), and ignore.

-s style

This option specifies the style of the dumped zone file. Possible styles are full (the default) and relative. The full format is most suitable for processing automatically by a separate script. The relative format is more human-readable and is thus suitable for editing by hand. For named-checkzone, this does not have any effect unless it dumps the zone contents. It also does not have any meaning if the output format is not text.

-S mode

This option checks whether an SRV record refers to a CNAME. Possible modes are fail, warn (the default), and ignore.

-t directory

This option tells named to chroot to directory, so that include directives in the configuration file are processed as if run by a similarly chrooted named.

-T mode

This option checks whether Sender Policy Framework (SPF) records exist and issues a warning if an SPF-formatted TXT record is not also present. Possible modes are warn (the default) and ignore.

-w directory

This option instructs named to chdir to directory, so that relative filenames in master file $INCLUDE directives work. This is similar to the directory clause in named.conf.

-D

This option dumps the zone file in canonical format. This is always enabled for named-compilezone.

-W mode

This option specifies whether to check for non-terminal wildcards. Non-terminal wildcards are almost always the result of a failure to understand the wildcard matching algorithm (RFC 1034). Possible modes are warn (the default) and ignore.

zonename

This indicates the domain name of the zone being checked.

filename

This is the name of the zone file.

Return Values¶

named-checkzone returns an exit status of 1 if errors were detected and 0 otherwise.

named-journalprint - print zone journal in human-readable form¶

Synopsis¶

named-journalprint [-c serial] [-dux] {journal}

Description¶

named-journalprint scans the contents of a zone journal file, printing it in a human-readable form, or, optionally, converting it to a different journal file format.

Journal files are automatically created by named when changes are made to dynamic zones (e.g., by nsupdate). They record each addition or deletion of a resource record, in binary format, allowing the changes to be re-applied to the zone when the server is restarted after a shutdown or crash. By default, the name of the journal file is formed by appending the extension .jnl to the name of the corresponding zone file.

named-journalprint converts the contents of a given journal file into a human-readable text format. Each line begins with add or del, to indicate whether the record was added or deleted, and continues with the resource record in master-file format.

The -c (compact) option provides a mechanism to reduce the size of a journal by removing (most/all) transactions prior to the specified serial number. Note: this option must not be used while named is running, and can cause data loss if the zone file has not been updated to contain the data being removed from the journal. Use with extreme caution.

The -x option causes additional data about the journal file to be printed at the beginning of the output and before each group of changes.

The -u (upgrade) and -d (downgrade) options recreate the journal file with a modified format version. The existing journal file is replaced. -d writes out the journal in the format used by versions of BIND up to 9.16.11; -u writes it out in the format used by versions since 9.16.13. (9.16.12 is omitted due to a journal-formatting bug in that release.) Note that these options must not be used while named is running.

named-nzd2nzf - convert an NZD database to NZF text format¶

Synopsis¶

named-nzd2nzf {filename}

Description¶

named-nzd2nzf converts an NZD database to NZF format and prints it to standard output. This can be used to review the configuration of zones that were added to named via rndc addzone. It can also be used to restore the old file format when rolling back from a newer version of BIND to an older version.

Arguments¶

filename: This is the name of the .nzd file whose contents should be printed.

named-rrchecker - syntax checker for individual DNS resource records¶

Synopsis¶

named-rrchecker [-h] [-o origin] [-p] [-u] [-C] [-T] [-P]

Description¶

named-rrchecker reads a individual DNS resource record from standard input and checks whether it is syntactically correct.

Options¶

-h: This option prints out the help menu.
-o origin: This option specifies the origin to be used when interpreting the record.
-p: This option prints out the resulting record in canonical form. If there is no canonical form defined, the record is printed in unknown record format.
-u: This option prints out the resulting record in unknown record form.
-C, -T, and -P: These options print out the known class, standard type, and private type mnemonics, respectively.

named.conf - configuration file for named¶

Synopsis¶

named.conf

Description¶

named.conf is the configuration file for named. Statements are enclosed in braces and terminated with a semi-colon. Clauses in the statements are also semi-colon terminated. The usual comment styles are supported:

C style: /* */

C++ style: // to end of line

Unix style: # to end of line

ACL¶

acl string { address_match_element; ... };

CONTROLS¶

controls {
      inet ( ipv4_address | ipv6_address |
          * ) [ port ( integer | * ) ] allow
          { address_match_element; ... } [
          keys { string; ... } ] [ read-only
          boolean ];
      unix quoted_string perm integer
          owner integer group integer [
          keys { string; ... } ] [ read-only
          boolean ];
};

DLZ¶

dlz string {
      database string;
      search boolean;
};

DNSSEC-POLICY¶

dnssec-policy string {
      dnskey-ttl duration;
      keys { ( csk | ksk | zsk ) [ ( key-directory ) ] lifetime
          duration_or_unlimited algorithm string [ integer ]; ... };
      max-zone-ttl duration;
      nsec3param [ iterations integer ] [ optout boolean ] [
          salt-length integer ];
      parent-ds-ttl duration;
      parent-propagation-delay duration;
      publish-safety duration;
      purge-keys duration;
      retire-safety duration;
      signatures-refresh duration;
      signatures-validity duration;
      signatures-validity-dnskey duration;
      zone-propagation-delay duration;
};

DYNDB¶

dyndb string quoted_string {
    unspecified-text };

KEY¶

key string {
      algorithm string;
      secret string;
};

LOGGING¶

logging {
      category string { string; ... };
      channel string {
              buffered boolean;
              file quoted_string [ versions ( unlimited | integer ) ]
                  [ size size ] [ suffix ( increment | timestamp ) ];
              null;
              print-category boolean;
              print-severity boolean;
              print-time ( iso8601 | iso8601-utc | local | boolean );
              severity log_severity;
              stderr;
              syslog [ syslog_facility ];
      };
};

MANAGED-KEYS¶

See DNSSEC-KEYS.

managed-keys { string ( static-key
    | initial-key | static-ds |
    initial-ds ) integer integer
    integer quoted_string; ... };, deprecated

MASTERS¶

masters string [ port integer ] [ dscp
    integer ] { ( remote-servers |
    ipv4_address [ port integer ] |
    ipv6_address [ port integer ] ) [ key
    string ]; ... };

OPTIONS¶

options {
      allow-new-zones boolean;
      allow-notify { address_match_element; ... };
      allow-query { address_match_element; ... };
      allow-query-cache { address_match_element; ... };
      allow-query-cache-on { address_match_element; ... };
      allow-query-on { address_match_element; ... };
      allow-recursion { address_match_element; ... };
      allow-recursion-on { address_match_element; ... };
      allow-transfer { address_match_element; ... };
      allow-update { address_match_element; ... };
      allow-update-forwarding { address_match_element; ... };
      also-notify [ port integer ] [ dscp integer ] { (
          remote-servers | ipv4_address [ port integer ] |
          ipv6_address [ port integer ] ) [ key string ]; ... };
      alt-transfer-source ( ipv4_address | * ) [ port ( integer | * )
          ] [ dscp integer ];
      alt-transfer-source-v6 ( ipv6_address | * ) [ port ( integer |
          * ) ] [ dscp integer ];
      answer-cookie boolean;
      attach-cache string;
      auth-nxdomain boolean; // default changed
      auto-dnssec ( allow | maintain | off );
      automatic-interface-scan boolean;
      avoid-v4-udp-ports { portrange; ... };
      avoid-v6-udp-ports { portrange; ... };
      bindkeys-file quoted_string;
      blackhole { address_match_element; ... };
      cache-file quoted_string;
      catalog-zones { zone string [ default-masters [ port integer ]
          [ dscp integer ] { ( remote-servers | ipv4_address [ port
          integer ] | ipv6_address [ port integer ] ) [ key
          string ]; ... } ] [ zone-directory quoted_string ] [
          in-memory boolean ] [ min-update-interval duration ]; ... };
      check-dup-records ( fail | warn | ignore );
      check-integrity boolean;
      check-mx ( fail | warn | ignore );
      check-mx-cname ( fail | warn | ignore );
      check-names ( primary | master |
          secondary | slave | response ) (
          fail | warn | ignore );
      check-sibling boolean;
      check-spf ( warn | ignore );
      check-srv-cname ( fail | warn | ignore );
      check-wildcard boolean;
      clients-per-query integer;
      cookie-algorithm ( aes | siphash24 );
      cookie-secret string;
      coresize ( default | unlimited | sizeval );
      datasize ( default | unlimited | sizeval );
      deny-answer-addresses { address_match_element; ... } [
          except-from { string; ... } ];
      deny-answer-aliases { string; ... } [ except-from { string; ...
          } ];
      dialup ( notify | notify-passive | passive | refresh | boolean );
      directory quoted_string;
      disable-algorithms string { string;
          ... };
      disable-ds-digests string { string;
          ... };
      disable-empty-zone string;
      dns64 netprefix {
              break-dnssec boolean;
              clients { address_match_element; ... };
              exclude { address_match_element; ... };
              mapped { address_match_element; ... };
              recursive-only boolean;
              suffix ipv6_address;
      };
      dns64-contact string;
      dns64-server string;
      dnskey-sig-validity integer;
      dnsrps-enable boolean;
      dnsrps-options { unspecified-text };
      dnssec-accept-expired boolean;
      dnssec-dnskey-kskonly boolean;
      dnssec-loadkeys-interval integer;
      dnssec-must-be-secure string boolean;
      dnssec-policy string;
      dnssec-secure-to-insecure boolean;
      dnssec-update-mode ( maintain | no-resign );
      dnssec-validation ( yes | no | auto );
      dnstap { ( all | auth | client | forwarder | resolver | update ) [
          ( query | response ) ]; ... };
      dnstap-identity ( quoted_string | none | hostname );
      dnstap-output ( file | unix ) quoted_string [ size ( unlimited |
          size ) ] [ versions ( unlimited | integer ) ] [ suffix (
          increment | timestamp ) ];
      dnstap-version ( quoted_string | none );
      dscp integer;
      dual-stack-servers [ port integer ] { ( quoted_string [ port
          integer ] [ dscp integer ] | ipv4_address [ port
          integer ] [ dscp integer ] | ipv6_address [ port
          integer ] [ dscp integer ] ); ... };
      dump-file quoted_string;
      edns-udp-size integer;
      empty-contact string;
      empty-server string;
      empty-zones-enable boolean;
      fetch-quota-params integer fixedpoint fixedpoint fixedpoint;
      fetches-per-server integer [ ( drop | fail ) ];
      fetches-per-zone integer [ ( drop | fail ) ];
      files ( default | unlimited | sizeval );
      flush-zones-on-shutdown boolean;
      forward ( first | only );
      forwarders [ port integer ] [ dscp integer ] { ( ipv4_address
          | ipv6_address ) [ port integer ] [ dscp integer ]; ... };
      fstrm-set-buffer-hint integer;
      fstrm-set-flush-timeout integer;
      fstrm-set-input-queue-size integer;
      fstrm-set-output-notify-threshold integer;
      fstrm-set-output-queue-model ( mpsc | spsc );
      fstrm-set-output-queue-size integer;
      fstrm-set-reopen-interval duration;
      geoip-directory ( quoted_string | none );
      glue-cache boolean;
      heartbeat-interval integer;
      hostname ( quoted_string | none );
      interface-interval duration;
      ixfr-from-differences ( primary | master | secondary | slave |
          boolean );
      keep-response-order { address_match_element; ... };
      key-directory quoted_string;
      lame-ttl duration;
      listen-on [ port integer ] [ dscp
          integer ] {
          address_match_element; ... };
      listen-on-v6 [ port integer ] [ dscp
          integer ] {
          address_match_element; ... };
      lmdb-mapsize sizeval;
      lock-file ( quoted_string | none );
      managed-keys-directory quoted_string;
      masterfile-format ( map | raw | text );
      masterfile-style ( full | relative );
      match-mapped-addresses boolean;
      max-cache-size ( default | unlimited | sizeval | percentage );
      max-cache-ttl duration;
      max-clients-per-query integer;
      max-ixfr-ratio ( unlimited | percentage );
      max-journal-size ( default | unlimited | sizeval );
      max-ncache-ttl duration;
      max-records integer;
      max-recursion-depth integer;
      max-recursion-queries integer;
      max-refresh-time integer;
      max-retry-time integer;
      max-rsa-exponent-size integer;
      max-stale-ttl duration;
      max-transfer-idle-in integer;
      max-transfer-idle-out integer;
      max-transfer-time-in integer;
      max-transfer-time-out integer;
      max-udp-size integer;
      max-zone-ttl ( unlimited | duration );
      memstatistics boolean;
      memstatistics-file quoted_string;
      message-compression boolean;
      min-cache-ttl duration;
      min-ncache-ttl duration;
      min-refresh-time integer;
      min-retry-time integer;
      minimal-any boolean;
      minimal-responses ( no-auth | no-auth-recursive | boolean );
      multi-master boolean;
      new-zones-directory quoted_string;
      no-case-compress { address_match_element; ... };
      nocookie-udp-size integer;
      notify ( explicit | master-only | primary-only | boolean );
      notify-delay integer;
      notify-rate integer;
      notify-source ( ipv4_address | * ) [ port ( integer | * ) ] [
          dscp integer ];
      notify-source-v6 ( ipv6_address | * ) [ port ( integer | * ) ]
          [ dscp integer ];
      notify-to-soa boolean;
      nta-lifetime duration;
      nta-recheck duration;
      nxdomain-redirect string;
      parental-source ( ipv4_address | * ) [ port ( integer | * ) ] [
          dscp integer ];
      parental-source-v6 ( ipv6_address | * ) [ port ( integer | * )
          ] [ dscp integer ];
      pid-file ( quoted_string | none );
      port integer;
      preferred-glue string;
      prefetch integer [ integer ];
      provide-ixfr boolean;
      qname-minimization ( strict | relaxed | disabled | off );
      query-source ( ( [ address ] ( ipv4_address | * ) [ port (
          integer | * ) ] ) | ( [ [ address ] ( ipv4_address | * ) ]
          port ( integer | * ) ) ) [ dscp integer ];
      query-source-v6 ( ( [ address ] ( ipv6_address | * ) [ port (
          integer | * ) ] ) | ( [ [ address ] ( ipv6_address | * ) ]
          port ( integer | * ) ) ) [ dscp integer ];
      querylog boolean;
      random-device ( quoted_string | none );
      rate-limit {
              all-per-second integer;
              errors-per-second integer;
              exempt-clients { address_match_element; ... };
              ipv4-prefix-length integer;
              ipv6-prefix-length integer;
              log-only boolean;
              max-table-size integer;
              min-table-size integer;
              nodata-per-second integer;
              nxdomains-per-second integer;
              qps-scale integer;
              referrals-per-second integer;
              responses-per-second integer;
              slip integer;
              window integer;
      };
      recursing-file quoted_string;
      recursion boolean;
      recursive-clients integer;
      request-expire boolean;
      request-ixfr boolean;
      request-nsid boolean;
      require-server-cookie boolean;
      reserved-sockets integer;
      resolver-nonbackoff-tries integer;
      resolver-query-timeout integer;
      resolver-retry-interval integer;
      response-padding { address_match_element; ... } block-size
          integer;
      response-policy { zone string [ add-soa boolean ] [ log
          boolean ] [ max-policy-ttl duration ] [ min-update-interval
          duration ] [ policy ( cname | disabled | drop | given | no-op
          | nodata | nxdomain | passthru | tcp-only quoted_string ) ] [
          recursive-only boolean ] [ nsip-enable boolean ] [
          nsdname-enable boolean ]; ... } [ add-soa boolean ] [
          break-dnssec boolean ] [ max-policy-ttl duration ] [
          min-update-interval duration ] [ min-ns-dots integer ] [
          nsip-wait-recurse boolean ] [ qname-wait-recurse boolean ]
          [ recursive-only boolean ] [ nsip-enable boolean ] [
          nsdname-enable boolean ] [ dnsrps-enable boolean ] [
          dnsrps-options { unspecified-text } ];
      root-delegation-only [ exclude { string; ... } ];
      root-key-sentinel boolean;
      rrset-order { [ class string ] [ type string ] [ name
          quoted_string ] string string; ... };
      secroots-file quoted_string;
      send-cookie boolean;
      serial-query-rate integer;
      serial-update-method ( date | increment | unixtime );
      server-id ( quoted_string | none | hostname );
      servfail-ttl duration;
      session-keyalg string;
      session-keyfile ( quoted_string | none );
      session-keyname string;
      sig-signing-nodes integer;
      sig-signing-signatures integer;
      sig-signing-type integer;
      sig-validity-interval integer [ integer ];
      sortlist { address_match_element; ... };
      stacksize ( default | unlimited | sizeval );
      stale-answer-client-timeout ( disabled | off | integer );
      stale-answer-enable boolean;
      stale-answer-ttl duration;
      stale-cache-enable boolean;
      stale-refresh-time duration;
      startup-notify-rate integer;
      statistics-file quoted_string;
      synth-from-dnssec boolean;
      tcp-advertised-timeout integer;
      tcp-clients integer;
      tcp-idle-timeout integer;
      tcp-initial-timeout integer;
      tcp-keepalive-timeout integer;
      tcp-listen-queue integer;
      tkey-dhkey quoted_string integer;
      tkey-domain quoted_string;
      tkey-gssapi-credential quoted_string;
      tkey-gssapi-keytab quoted_string;
      transfer-format ( many-answers | one-answer );
      transfer-message-size integer;
      transfer-source ( ipv4_address | * ) [ port ( integer | * ) ] [
          dscp integer ];
      transfer-source-v6 ( ipv6_address | * ) [ port ( integer | * )
          ] [ dscp integer ];
      transfers-in integer;
      transfers-out integer;
      transfers-per-ns integer;
      trust-anchor-telemetry boolean; // experimental
      try-tcp-refresh boolean;
      update-check-ksk boolean;
      use-alt-transfer-source boolean;
      use-v4-udp-ports { portrange; ... };
      use-v6-udp-ports { portrange; ... };
      v6-bias integer;
      validate-except { string; ... };
      version ( quoted_string | none );
      zero-no-soa-ttl boolean;
      zero-no-soa-ttl-cache boolean;
      zone-statistics ( full | terse | none | boolean );
};

PARENTAL-AGENTS¶

parental-agents string [ port integer ] [
    dscp integer ] { ( remote-servers |
    ipv4_address [ port integer ] |
    ipv6_address [ port integer ] ) [ key
    string ]; ... };

PLUGIN¶

plugin ( query ) string [ { unspecified-text
    } ];

PRIMARIES¶

primaries string [ port integer ] [ dscp
    integer ] { ( remote-servers |
    ipv4_address [ port integer ] |
    ipv6_address [ port integer ] ) [ key
    string ]; ... };

SERVER¶

server netprefix {
      bogus boolean;
      edns boolean;
      edns-udp-size integer;
      edns-version integer;
      keys server_key;
      max-udp-size integer;
      notify-source ( ipv4_address | * ) [ port ( integer | * ) ] [
          dscp integer ];
      notify-source-v6 ( ipv6_address | * ) [ port ( integer | * ) ]
          [ dscp integer ];
      padding integer;
      provide-ixfr boolean;
      query-source ( ( [ address ] ( ipv4_address | * ) [ port (
          integer | * ) ] ) | ( [ [ address ] ( ipv4_address | * ) ]
          port ( integer | * ) ) ) [ dscp integer ];
      query-source-v6 ( ( [ address ] ( ipv6_address | * ) [ port (
          integer | * ) ] ) | ( [ [ address ] ( ipv6_address | * ) ]
          port ( integer | * ) ) ) [ dscp integer ];
      request-expire boolean;
      request-ixfr boolean;
      request-nsid boolean;
      send-cookie boolean;
      tcp-keepalive boolean;
      tcp-only boolean;
      transfer-format ( many-answers | one-answer );
      transfer-source ( ipv4_address | * ) [ port ( integer | * ) ] [
          dscp integer ];
      transfer-source-v6 ( ipv6_address | * ) [ port ( integer | * )
          ] [ dscp integer ];
      transfers integer;
};

STATISTICS-CHANNELS¶

statistics-channels {
      inet ( ipv4_address | ipv6_address |
          * ) [ port ( integer | * ) ] [
          allow { address_match_element; ...
          } ];
};

TRUST-ANCHORS¶

trust-anchors { string ( static-key |
    initial-key | static-ds | initial-ds )
    integer integer integer
    quoted_string; ... };

TRUSTED-KEYS¶

Deprecated - see DNSSEC-KEYS.

trusted-keys { string integer
    integer integer
    quoted_string; ... };, deprecated

VIEW¶

view string [ class ] {
      allow-new-zones boolean;
      allow-notify { address_match_element; ... };
      allow-query { address_match_element; ... };
      allow-query-cache { address_match_element; ... };
      allow-query-cache-on { address_match_element; ... };
      allow-query-on { address_match_element; ... };
      allow-recursion { address_match_element; ... };
      allow-recursion-on { address_match_element; ... };
      allow-transfer { address_match_element; ... };
      allow-update { address_match_element; ... };
      allow-update-forwarding { address_match_element; ... };
      also-notify [ port integer ] [ dscp integer ] { (
          remote-servers | ipv4_address [ port integer ] |
          ipv6_address [ port integer ] ) [ key string ]; ... };
      alt-transfer-source ( ipv4_address | * ) [ port ( integer | * )
          ] [ dscp integer ];
      alt-transfer-source-v6 ( ipv6_address | * ) [ port ( integer |
          * ) ] [ dscp integer ];
      attach-cache string;
      auth-nxdomain boolean; // default changed
      auto-dnssec ( allow | maintain | off );
      cache-file quoted_string;
      catalog-zones { zone string [ default-masters [ port integer ]
          [ dscp integer ] { ( remote-servers | ipv4_address [ port
          integer ] | ipv6_address [ port integer ] ) [ key
          string ]; ... } ] [ zone-directory quoted_string ] [
          in-memory boolean ] [ min-update-interval duration ]; ... };
      check-dup-records ( fail | warn | ignore );
      check-integrity boolean;
      check-mx ( fail | warn | ignore );
      check-mx-cname ( fail | warn | ignore );
      check-names ( primary | master |
          secondary | slave | response ) (
          fail | warn | ignore );
      check-sibling boolean;
      check-spf ( warn | ignore );
      check-srv-cname ( fail | warn | ignore );
      check-wildcard boolean;
      clients-per-query integer;
      deny-answer-addresses { address_match_element; ... } [
          except-from { string; ... } ];
      deny-answer-aliases { string; ... } [ except-from { string; ...
          } ];
      dialup ( notify | notify-passive | passive | refresh | boolean );
      disable-algorithms string { string;
          ... };
      disable-ds-digests string { string;
          ... };
      disable-empty-zone string;
      dlz string {
              database string;
              search boolean;
      };
      dns64 netprefix {
              break-dnssec boolean;
              clients { address_match_element; ... };
              exclude { address_match_element; ... };
              mapped { address_match_element; ... };
              recursive-only boolean;
              suffix ipv6_address;
      };
      dns64-contact string;
      dns64-server string;
      dnskey-sig-validity integer;
      dnsrps-enable boolean;
      dnsrps-options { unspecified-text };
      dnssec-accept-expired boolean;
      dnssec-dnskey-kskonly boolean;
      dnssec-loadkeys-interval integer;
      dnssec-must-be-secure string boolean;
      dnssec-policy string;
      dnssec-secure-to-insecure boolean;
      dnssec-update-mode ( maintain | no-resign );
      dnssec-validation ( yes | no | auto );
      dnstap { ( all | auth | client | forwarder | resolver | update ) [
          ( query | response ) ]; ... };
      dual-stack-servers [ port integer ] { ( quoted_string [ port
          integer ] [ dscp integer ] | ipv4_address [ port
          integer ] [ dscp integer ] | ipv6_address [ port
          integer ] [ dscp integer ] ); ... };
      dyndb string quoted_string {
          unspecified-text };
      edns-udp-size integer;
      empty-contact string;
      empty-server string;
      empty-zones-enable boolean;
      fetch-quota-params integer fixedpoint fixedpoint fixedpoint;
      fetches-per-server integer [ ( drop | fail ) ];
      fetches-per-zone integer [ ( drop | fail ) ];
      forward ( first | only );
      forwarders [ port integer ] [ dscp integer ] { ( ipv4_address
          | ipv6_address ) [ port integer ] [ dscp integer ]; ... };
      glue-cache boolean;
      ixfr-from-differences ( primary | master | secondary | slave |
          boolean );
      key string {
              algorithm string;
              secret string;
      };
      key-directory quoted_string;
      lame-ttl duration;
      lmdb-mapsize sizeval;
      managed-keys { string (
          static-key | initial-key
          | static-ds | initial-ds
          ) integer integer
          integer
          quoted_string; ... };, deprecated
      masterfile-format ( map | raw | text );
      masterfile-style ( full | relative );
      match-clients { address_match_element; ... };
      match-destinations { address_match_element; ... };
      match-recursive-only boolean;
      max-cache-size ( default | unlimited | sizeval | percentage );
      max-cache-ttl duration;
      max-clients-per-query integer;
      max-ixfr-ratio ( unlimited | percentage );
      max-journal-size ( default | unlimited | sizeval );
      max-ncache-ttl duration;
      max-records integer;
      max-recursion-depth integer;
      max-recursion-queries integer;
      max-refresh-time integer;
      max-retry-time integer;
      max-stale-ttl duration;
      max-transfer-idle-in integer;
      max-transfer-idle-out integer;
      max-transfer-time-in integer;
      max-transfer-time-out integer;
      max-udp-size integer;
      max-zone-ttl ( unlimited | duration );
      message-compression boolean;
      min-cache-ttl duration;
      min-ncache-ttl duration;
      min-refresh-time integer;
      min-retry-time integer;
      minimal-any boolean;
      minimal-responses ( no-auth | no-auth-recursive | boolean );
      multi-master boolean;
      new-zones-directory quoted_string;
      no-case-compress { address_match_element; ... };
      nocookie-udp-size integer;
      notify ( explicit | master-only | primary-only | boolean );
      notify-delay integer;
      notify-source ( ipv4_address | * ) [ port ( integer | * ) ] [
          dscp integer ];
      notify-source-v6 ( ipv6_address | * ) [ port ( integer | * ) ]
          [ dscp integer ];
      notify-to-soa boolean;
      nta-lifetime duration;
      nta-recheck duration;
      nxdomain-redirect string;
      parental-source ( ipv4_address | * ) [ port ( integer | * ) ] [
          dscp integer ];
      parental-source-v6 ( ipv6_address | * ) [ port ( integer | * )
          ] [ dscp integer ];
      plugin ( query ) string [ {
          unspecified-text } ];
      preferred-glue string;
      prefetch integer [ integer ];
      provide-ixfr boolean;
      qname-minimization ( strict | relaxed | disabled | off );
      query-source ( ( [ address ] ( ipv4_address | * ) [ port (
          integer | * ) ] ) | ( [ [ address ] ( ipv4_address | * ) ]
          port ( integer | * ) ) ) [ dscp integer ];
      query-source-v6 ( ( [ address ] ( ipv6_address | * ) [ port (
          integer | * ) ] ) | ( [ [ address ] ( ipv6_address | * ) ]
          port ( integer | * ) ) ) [ dscp integer ];
      rate-limit {
              all-per-second integer;
              errors-per-second integer;
              exempt-clients { address_match_element; ... };
              ipv4-prefix-length integer;
              ipv6-prefix-length integer;
              log-only boolean;
              max-table-size integer;
              min-table-size integer;
              nodata-per-second integer;
              nxdomains-per-second integer;
              qps-scale integer;
              referrals-per-second integer;
              responses-per-second integer;
              slip integer;
              window integer;
      };
      recursion boolean;
      request-expire boolean;
      request-ixfr boolean;
      request-nsid boolean;
      require-server-cookie boolean;
      resolver-nonbackoff-tries integer;
      resolver-query-timeout integer;
      resolver-retry-interval integer;
      response-padding { address_match_element; ... } block-size
          integer;
      response-policy { zone string [ add-soa boolean ] [ log
          boolean ] [ max-policy-ttl duration ] [ min-update-interval
          duration ] [ policy ( cname | disabled | drop | given | no-op
          | nodata | nxdomain | passthru | tcp-only quoted_string ) ] [
          recursive-only boolean ] [ nsip-enable boolean ] [
          nsdname-enable boolean ]; ... } [ add-soa boolean ] [
          break-dnssec boolean ] [ max-policy-ttl duration ] [
          min-update-interval duration ] [ min-ns-dots integer ] [
          nsip-wait-recurse boolean ] [ qname-wait-recurse boolean ]
          [ recursive-only boolean ] [ nsip-enable boolean ] [
          nsdname-enable boolean ] [ dnsrps-enable boolean ] [
          dnsrps-options { unspecified-text } ];
      root-delegation-only [ exclude { string; ... } ];
      root-key-sentinel boolean;
      rrset-order { [ class string ] [ type string ] [ name
          quoted_string ] string string; ... };
      send-cookie boolean;
      serial-update-method ( date | increment | unixtime );
      server netprefix {
              bogus boolean;
              edns boolean;
              edns-udp-size integer;
              edns-version integer;
              keys server_key;
              max-udp-size integer;
              notify-source ( ipv4_address | * ) [ port ( integer | *
                  ) ] [ dscp integer ];
              notify-source-v6 ( ipv6_address | * ) [ port ( integer
                  | * ) ] [ dscp integer ];
              padding integer;
              provide-ixfr boolean;
              query-source ( ( [ address ] ( ipv4_address | * ) [ port
                  ( integer | * ) ] ) | ( [ [ address ] (
                  ipv4_address | * ) ] port ( integer | * ) ) ) [
                  dscp integer ];
              query-source-v6 ( ( [ address ] ( ipv6_address | * ) [
                  port ( integer | * ) ] ) | ( [ [ address ] (
                  ipv6_address | * ) ] port ( integer | * ) ) ) [
                  dscp integer ];
              request-expire boolean;
              request-ixfr boolean;
              request-nsid boolean;
              send-cookie boolean;
              tcp-keepalive boolean;
              tcp-only boolean;
              transfer-format ( many-answers | one-answer );
              transfer-source ( ipv4_address | * ) [ port ( integer |
                  * ) ] [ dscp integer ];
              transfer-source-v6 ( ipv6_address | * ) [ port (
                  integer | * ) ] [ dscp integer ];
              transfers integer;
      };
      servfail-ttl duration;
      sig-signing-nodes integer;
      sig-signing-signatures integer;
      sig-signing-type integer;
      sig-validity-interval integer [ integer ];
      sortlist { address_match_element; ... };
      stale-answer-client-timeout ( disabled | off | integer );
      stale-answer-enable boolean;
      stale-answer-ttl duration;
      stale-cache-enable boolean;
      stale-refresh-time duration;
      synth-from-dnssec boolean;
      transfer-format ( many-answers | one-answer );
      transfer-source ( ipv4_address | * ) [ port ( integer | * ) ] [
          dscp integer ];
      transfer-source-v6 ( ipv6_address | * ) [ port ( integer | * )
          ] [ dscp integer ];
      trust-anchor-telemetry boolean; // experimental
      trust-anchors { string ( static-key |
          initial-key | static-ds | initial-ds
          ) integer integer integer
          quoted_string; ... };
      trusted-keys { string
          integer integer
          integer
          quoted_string; ... };, deprecated
      try-tcp-refresh boolean;
      update-check-ksk boolean;
      use-alt-transfer-source boolean;
      v6-bias integer;
      validate-except { string; ... };
      zero-no-soa-ttl boolean;
      zero-no-soa-ttl-cache boolean;
      zone string [ class ] {
              allow-notify { address_match_element; ... };
              allow-query { address_match_element; ... };
              allow-query-on { address_match_element; ... };
              allow-transfer { address_match_element; ... };
              allow-update { address_match_element; ... };
              allow-update-forwarding { address_match_element; ... };
              also-notify [ port integer ] [ dscp integer ] { (
                  remote-servers | ipv4_address [ port integer ] |
                  ipv6_address [ port integer ] ) [ key string ];
                  ... };
              alt-transfer-source ( ipv4_address | * ) [ port (
                  integer | * ) ] [ dscp integer ];
              alt-transfer-source-v6 ( ipv6_address | * ) [ port (
                  integer | * ) ] [ dscp integer ];
              auto-dnssec ( allow | maintain | off );
              check-dup-records ( fail | warn | ignore );
              check-integrity boolean;
              check-mx ( fail | warn | ignore );
              check-mx-cname ( fail | warn | ignore );
              check-names ( fail | warn | ignore );
              check-sibling boolean;
              check-spf ( warn | ignore );
              check-srv-cname ( fail | warn | ignore );
              check-wildcard boolean;
              database string;
              delegation-only boolean;
              dialup ( notify | notify-passive | passive | refresh |
                  boolean );
              dlz string;
              dnskey-sig-validity integer;
              dnssec-dnskey-kskonly boolean;
              dnssec-loadkeys-interval integer;
              dnssec-policy string;
              dnssec-secure-to-insecure boolean;
              dnssec-update-mode ( maintain | no-resign );
              file quoted_string;
              forward ( first | only );
              forwarders [ port integer ] [ dscp integer ] { (
                  ipv4_address | ipv6_address ) [ port integer ] [
                  dscp integer ]; ... };
              in-view string;
              inline-signing boolean;
              ixfr-from-differences boolean;
              journal quoted_string;
              key-directory quoted_string;
              masterfile-format ( map | raw | text );
              masterfile-style ( full | relative );
              masters [ port integer ] [ dscp integer ] { (
                  remote-servers | ipv4_address [ port integer ] |
                  ipv6_address [ port integer ] ) [ key string ];
                  ... };
              max-ixfr-ratio ( unlimited | percentage );
              max-journal-size ( default | unlimited | sizeval );
              max-records integer;
              max-refresh-time integer;
              max-retry-time integer;
              max-transfer-idle-in integer;
              max-transfer-idle-out integer;
              max-transfer-time-in integer;
              max-transfer-time-out integer;
              max-zone-ttl ( unlimited | duration );
              min-refresh-time integer;
              min-retry-time integer;
              multi-master boolean;
              notify ( explicit | master-only | primary-only | boolean );
              notify-delay integer;
              notify-source ( ipv4_address | * ) [ port ( integer | *
                  ) ] [ dscp integer ];
              notify-source-v6 ( ipv6_address | * ) [ port ( integer
                  | * ) ] [ dscp integer ];
              notify-to-soa boolean;
              parental-agents [ port integer ] [ dscp integer ] { (
                  remote-servers | ipv4_address [ port integer ] |
                  ipv6_address [ port integer ] ) [ key string ];
                  ... };
              parental-source ( ipv4_address | * ) [ port ( integer |
                  * ) ] [ dscp integer ];
              parental-source-v6 ( ipv6_address | * ) [ port (
                  integer | * ) ] [ dscp integer ];
              primaries [ port integer ] [ dscp integer ] { (
                  remote-servers | ipv4_address [ port integer ] |
                  ipv6_address [ port integer ] ) [ key string ];
                  ... };
              request-expire boolean;
              request-ixfr boolean;
              serial-update-method ( date | increment | unixtime );
              server-addresses { ( ipv4_address | ipv6_address ); ... };
              server-names { string; ... };
              sig-signing-nodes integer;
              sig-signing-signatures integer;
              sig-signing-type integer;
              sig-validity-interval integer [ integer ];
              transfer-source ( ipv4_address | * ) [ port ( integer |
                  * ) ] [ dscp integer ];
              transfer-source-v6 ( ipv6_address | * ) [ port (
                  integer | * ) ] [ dscp integer ];
              try-tcp-refresh boolean;
              type ( primary | master | secondary | slave | mirror |
                  delegation-only | forward | hint | redirect |
                  static-stub | stub );
              update-check-ksk boolean;
              update-policy ( local | { ( deny | grant ) string (
                  6to4-self | external | krb5-self | krb5-selfsub |
                  krb5-subdomain | ms-self | ms-selfsub | ms-subdomain |
                  name | self | selfsub | selfwild | subdomain | tcp-self
                  | wildcard | zonesub ) [ string ] rrtypelist; ... };
              use-alt-transfer-source boolean;
              zero-no-soa-ttl boolean;
              zone-statistics ( full | terse | none | boolean );
      };
      zone-statistics ( full | terse | none | boolean );
};

ZONE¶

zone string [ class ] {
      allow-notify { address_match_element; ... };
      allow-query { address_match_element; ... };
      allow-query-on { address_match_element; ... };
      allow-transfer { address_match_element; ... };
      allow-update { address_match_element; ... };
      allow-update-forwarding { address_match_element; ... };
      also-notify [ port integer ] [ dscp integer ] { (
          remote-servers | ipv4_address [ port integer ] |
          ipv6_address [ port integer ] ) [ key string ]; ... };
      alt-transfer-source ( ipv4_address | * ) [ port ( integer | * )
          ] [ dscp integer ];
      alt-transfer-source-v6 ( ipv6_address | * ) [ port ( integer |
          * ) ] [ dscp integer ];
      auto-dnssec ( allow | maintain | off );
      check-dup-records ( fail | warn | ignore );
      check-integrity boolean;
      check-mx ( fail | warn | ignore );
      check-mx-cname ( fail | warn | ignore );
      check-names ( fail | warn | ignore );
      check-sibling boolean;
      check-spf ( warn | ignore );
      check-srv-cname ( fail | warn | ignore );
      check-wildcard boolean;
      database string;
      delegation-only boolean;
      dialup ( notify | notify-passive | passive | refresh | boolean );
      dlz string;
      dnskey-sig-validity integer;
      dnssec-dnskey-kskonly boolean;
      dnssec-loadkeys-interval integer;
      dnssec-policy string;
      dnssec-secure-to-insecure boolean;
      dnssec-update-mode ( maintain | no-resign );
      file quoted_string;
      forward ( first | only );
      forwarders [ port integer ] [ dscp integer ] { ( ipv4_address
          | ipv6_address ) [ port integer ] [ dscp integer ]; ... };
      in-view string;
      inline-signing boolean;
      ixfr-from-differences boolean;
      journal quoted_string;
      key-directory quoted_string;
      masterfile-format ( map | raw | text );
      masterfile-style ( full | relative );
      masters [ port integer ] [ dscp integer ] { ( remote-servers
          | ipv4_address [ port integer ] | ipv6_address [ port
          integer ] ) [ key string ]; ... };
      max-ixfr-ratio ( unlimited | percentage );
      max-journal-size ( default | unlimited | sizeval );
      max-records integer;
      max-refresh-time integer;
      max-retry-time integer;
      max-transfer-idle-in integer;
      max-transfer-idle-out integer;
      max-transfer-time-in integer;
      max-transfer-time-out integer;
      max-zone-ttl ( unlimited | duration );
      min-refresh-time integer;
      min-retry-time integer;
      multi-master boolean;
      notify ( explicit | master-only | primary-only | boolean );
      notify-delay integer;
      notify-source ( ipv4_address | * ) [ port ( integer | * ) ] [
          dscp integer ];
      notify-source-v6 ( ipv6_address | * ) [ port ( integer | * ) ]
          [ dscp integer ];
      notify-to-soa boolean;
      parental-agents [ port integer ] [ dscp integer ] { (
          remote-servers | ipv4_address [ port integer ] |
          ipv6_address [ port integer ] ) [ key string ]; ... };
      parental-source ( ipv4_address | * ) [ port ( integer | * ) ] [
          dscp integer ];
      parental-source-v6 ( ipv6_address | * ) [ port ( integer | * )
          ] [ dscp integer ];
      primaries [ port integer ] [ dscp integer ] { (
          remote-servers | ipv4_address [ port integer ] |
          ipv6_address [ port integer ] ) [ key string ]; ... };
      request-expire boolean;
      request-ixfr boolean;
      serial-update-method ( date | increment | unixtime );
      server-addresses { ( ipv4_address | ipv6_address ); ... };
      server-names { string; ... };
      sig-signing-nodes integer;
      sig-signing-signatures integer;
      sig-signing-type integer;
      sig-validity-interval integer [ integer ];
      transfer-source ( ipv4_address | * ) [ port ( integer | * ) ] [
          dscp integer ];
      transfer-source-v6 ( ipv6_address | * ) [ port ( integer | * )
          ] [ dscp integer ];
      try-tcp-refresh boolean;
      type ( primary | master | secondary | slave | mirror |
          delegation-only | forward | hint | redirect | static-stub |
          stub );
      update-check-ksk boolean;
      update-policy ( local | { ( deny | grant ) string ( 6to4-self |
          external | krb5-self | krb5-selfsub | krb5-subdomain | ms-self
          | ms-selfsub | ms-subdomain | name | self | selfsub | selfwild
          | subdomain | tcp-self | wildcard | zonesub ) [ string ]
          rrtypelist; ... };
      use-alt-transfer-source boolean;
      zero-no-soa-ttl boolean;
      zone-statistics ( full | terse | none | boolean );
};

Files¶

/etc/named.conf

named - Internet domain name server¶

Synopsis¶

named [ [-4] | [-6] ] [-c config-file] [-d debug-level] [-D string] [-E engine-name] [-f] [-g] [-L logfile] [-M option] [-m flag] [-n #cpus] [-p port] [-s] [-S #max-socks] [-t directory] [-U #listeners] [-u user] [-v] [-V] [-X lock-file] [-x cache-file]

Description¶

named is a Domain Name System (DNS) server, part of the BIND 9 distribution from ISC. For more information on the DNS, see RFC 1033, RFC 1034, and RFC 1035.

When invoked without arguments, named reads the default configuration file /etc/named.conf, reads any initial data, and listens for queries.

Options¶

-4

This option tells named to use only IPv4, even if the host machine is capable of IPv6. -4 and -6 are mutually exclusive.

-6

This option tells named to use only IPv6, even if the host machine is capable of IPv4. -4 and -6 are mutually exclusive.

-c config-file

This option tells named to use config-file as its configuration file instead of the default, /etc/named.conf. To ensure that the configuration file can be reloaded after the server has changed its working directory due to to a possible directory option in the configuration file, config-file should be an absolute pathname.

-d debug-level

This option sets the daemon’s debug level to debug-level. Debugging traces from named become more verbose as the debug level increases.

-D string

This option specifies a string that is used to identify a instance of named in a process listing. The contents of string are not examined.

-E engine-name

When applicable, this option specifies the hardware to use for cryptographic operations, such as a secure key store used for signing.

When BIND 9 is built with OpenSSL, this needs to be set to the OpenSSL engine identifier that drives the cryptographic accelerator or hardware service module (usually pkcs11). When BIND is built with native PKCS#11 cryptography (--enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via --with-pkcs11.

-f

This option runs the server in the foreground (i.e., do not daemonize).

-g

This option runs the server in the foreground and forces all logging to stderr.

-L logfile

This option sets the log to the file logfile by default, instead of the system log.

-M option

This option sets the default memory context options. If set to external, the internal memory manager is bypassed in favor of system-provided memory allocation functions. If set to fill, blocks of memory are filled with tag values when allocated or freed, to assist debugging of memory problems. nofill disables this behavior, and is the default unless named has been compiled with developer options.

-m flag

This option turns on memory usage debugging flags. Possible flags are usage, trace, record, size, and mctx. These correspond to the ISC_MEM_DEBUGXXXX flags described in <isc/mem.h>.

-n #cpus

This option creates #cpus worker threads to take advantage of multiple CPUs. If not specified, named tries to determine the number of CPUs present and creates one thread per CPU. If it is unable to determine the number of CPUs, a single worker thread is created.

-p port

This option listens for queries on port. If not specified, the default is port 53.

-s

This option writes memory usage statistics to stdout on exit.

Note

This option is mainly of interest to BIND 9 developers and may be removed or changed in a future release.

-S #max-socks: This option allows named to use up to #max-socks sockets. The default value is 21000 on systems built with default configuration options, and 4096 on systems built with configure --with-tuning=small.

Warning

This option should be unnecessary for the vast majority of users. The use of this option could even be harmful, because the specified value may exceed the limitation of the underlying system API. It is therefore set only when the default configuration causes exhaustion of file descriptors and the operational environment is known to support the specified number of sockets. Note also that the actual maximum number is normally slightly fewer than the specified value, because named reserves some file descriptors for its internal use.

-t directory: This option tells named to chroot to directory after processing the command-line arguments, but before reading the configuration file.

Warning

This option should be used in conjunction with the -u option, as chrooting a process running as root doesn’t enhance security on most systems; the way chroot is defined allows a process with root privileges to escape a chroot jail.

-U #listeners: This option tells named the number of #listeners worker threads to listen on, for incoming UDP packets on each address. If not specified, named calculates a default value based on the number of detected CPUs: 1 for 1 CPU, and the number of detected CPUs minus one for machines with more than 1 CPU. This cannot be increased to a value higher than the number of CPUs. If -n has been set to a higher value than the number of detected CPUs, then -U may be increased as high as that value, but no higher. On Windows, the number of UDP listeners is hardwired to 1 and this option has no effect.
-u user: This option sets the setuid to user after completing privileged operations, such as creating sockets that listen on privileged ports.

Note

On Linux, named uses the kernel’s capability mechanism to drop all root privileges except the ability to bind to a privileged port and set process resource limits. Unfortunately, this means that the -u option only works when named is run on kernel 2.2.18 or later, or kernel 2.3.99-pre3 or later, since previous kernels did not allow privileges to be retained after setuid.

-v: This option reports the version number and exits.
-V: This option reports the version number and build options, and exits.
-X lock-file: This option acquires a lock on the specified file at runtime; this helps to prevent duplicate named instances from running simultaneously. Use of this option overrides the lock-file option in named.conf. If set to none, the lock file check is disabled.
-x cache-file: This option loads data from cache-file into the cache of the default view.

Warning

This option must not be used in normal operations. It is only of interest to BIND 9 developers and may be removed or changed in a future release.

Signals¶

In routine operation, signals should not be used to control the nameserver; rndc should be used instead.

SIGHUP: This signal forces a reload of the server.
SIGINT, SIGTERM: These signals shut down the server.

The result of sending any other signals to the server is undefined.

Configuration¶

The named configuration file is too complex to describe in detail here. A complete description is provided in the BIND 9 Administrator Reference Manual.

named inherits the umask (file creation mode mask) from the parent process. If files created by named, such as journal files, need to have custom permissions, the umask should be set explicitly in the script used to start the named process.

Files¶

/etc/named.conf: The default configuration file.
/var/run/named/named.pid: The default process-id file.

nsec3hash - generate NSEC3 hash¶

Synopsis¶

nsec3hash {salt} {algorithm} {iterations} {domain}

nsec3hash -r {algorithm} {flags} {iterations} {salt} {domain}

Description¶

nsec3hash generates an NSEC3 hash based on a set of NSEC3 parameters. This can be used to check the validity of NSEC3 records in a signed zone.

If this command is invoked as nsec3hash -r, it takes arguments in order, matching the first four fields of an NSEC3 record followed by the domain name: algorithm, flags, iterations, salt, domain. This makes it convenient to copy and paste a portion of an NSEC3 or NSEC3PARAM record into a command line to confirm the correctness of an NSEC3 hash.

Arguments¶

salt: This is the salt provided to the hash algorithm.
algorithm: This is a number indicating the hash algorithm. Currently the only supported hash algorithm for NSEC3 is SHA-1, which is indicated by the number 1; consequently “1” is the only useful value for this argument.
flags: This is provided for compatibility with NSEC3 record presentation format, but is ignored since the flags do not affect the hash.
iterations: This is the number of additional times the hash should be performed.
domain: This is the domain name to be hashed.

nslookup - query Internet name servers interactively¶

Synopsis¶

nslookup [-option] [name | -] [server]

Description¶

nslookup is a program to query Internet domain name servers. nslookup has two modes: interactive and non-interactive. Interactive mode allows the user to query name servers for information about various hosts and domains or to print a list of hosts in a domain. Non-interactive mode prints just the name and requested information for a host or domain.

Arguments¶

Interactive mode is entered in the following cases:

when no arguments are given (the default name server is used);
when the first argument is a hyphen (-) and the second argument is the host name or Internet address of a name server.

Non-interactive mode is used when the name or Internet address of the host to be looked up is given as the first argument. The optional second argument specifies the host name or address of a name server.

Options can also be specified on the command line if they precede the arguments and are prefixed with a hyphen. For example, to change the default query type to host information, with an initial timeout of 10 seconds, type:

nslookup -query=hinfo  -timeout=10

The -version option causes nslookup to print the version number and immediately exit.

Interactive Commands¶

host [server]

This command looks up information for host using the current default server or using server, if specified. If host is an Internet address and the query type is A or PTR, the name of the host is returned. If host is a name and does not have a trailing period (.), the search list is used to qualify the name.

To look up a host not in the current domain, append a period to the name.

server domain | lserver domain

These commands change the default server to domain; lserver uses the initial server to look up information about domain, while server uses the current default server. If an authoritative answer cannot be found, the names of servers that might have the answer are returned.

root

This command is not implemented.

finger

This command is not implemented.

ls

This command is not implemented.

view

This command is not implemented.

help

This command is not implemented.

?

This command is not implemented.

exit

This command exits the program.

set keyword[=value]

This command is used to change state information that affects the lookups. Valid keywords are:

all

This keyword prints the current values of the frequently used options to set. Information about the current default server and host is also printed.

class=value

This keyword changes the query class to one of:

IN: the Internet class
CH: the Chaos class
HS: the Hesiod class
ANY: wildcard

The class specifies the protocol group of the information. The default is IN; the abbreviation for this keyword is cl.

nodebug

This keyword turns on or off the display of the full response packet, and any intermediate response packets, when searching. The default for this keyword is nodebug; the abbreviation for this keyword is [no]deb.

nod2

This keyword turns debugging mode on or off. This displays more about what nslookup is doing. The default is nod2.

domain=name

This keyword sets the search list to name.

nosearch

If the lookup request contains at least one period, but does not end with a trailing period, this keyword appends the domain names in the domain search list to the request until an answer is received. The default is search.

port=value

This keyword changes the default TCP/UDP name server port to value from its default, port 53. The abbreviation for this keyword is po.

querytype=value | type=value

This keyword changes the type of the information query to value. The defaults are A and then AAAA; the abbreviations for these keywords are q and ty.

Please note that it is only possible to specify one query type. Only the default behavior looks up both when an alternative is not specified.

norecurse

This keyword tells the name server to query other servers if it does not have the information. The default is recurse; the abbreviation for this keyword is [no]rec.

ndots=number

This keyword sets the number of dots (label separators) in a domain that disables searching. Absolute names always stop searching.

retry=number

This keyword sets the number of retries to number.

timeout=number

This keyword changes the initial timeout interval to wait for a reply to number, in seconds.

novc

This keyword indicates that a virtual circuit should always be used when sending requests to the server. novc is the default.

nofail

This keyword tries the next nameserver if a nameserver responds with SERVFAIL or a referral (nofail), or terminates the query (fail) on such a response. The default is nofail.

Return Values¶

nslookup returns with an exit status of 1 if any query failed, and 0 otherwise.

IDN Support¶

If nslookup has been built with IDN (internationalized domain name) support, it can accept and display non-ASCII domain names. nslookup appropriately converts character encoding of a domain name before sending a request to a DNS server or displaying a reply from the server. To turn off IDN support, define the IDN_DISABLE environment variable. IDN support is disabled if the variable is set when nslookup runs, or when the standard output is not a tty.

Files¶

/etc/resolv.conf

nsupdate - dynamic DNS update utility¶

Synopsis¶

Description¶

nsupdate is used to submit Dynamic DNS Update requests, as defined in RFC 2136, to a name server. This allows resource records to be added or removed from a zone without manually editing the zone file. A single update request can contain requests to add or remove more than one resource record.

Zones that are under dynamic control via nsupdate or a DHCP server should not be edited by hand. Manual edits could conflict with dynamic updates and cause data to be lost.

The resource records that are dynamically added or removed with nsupdate must be in the same zone. Requests are sent to the zone’s primary server, which is identified by the MNAME field of the zone’s SOA record.

Transaction signatures can be used to authenticate the Dynamic DNS updates. These use the TSIG resource record type described in RFC 2845, the SIG(0) record described in RFC 2535 and RFC 2931, or GSS-TSIG as described in RFC 3645.

TSIG relies on a shared secret that should only be known to nsupdate and the name server. For instance, suitable key and server statements are added to /etc/named.conf so that the name server can associate the appropriate secret key and algorithm with the IP address of the client application that is using TSIG authentication. ddns-confgen can generate suitable configuration fragments. nsupdate uses the -y or -k options to provide the TSIG shared secret; these options are mutually exclusive.

SIG(0) uses public key cryptography. To use a SIG(0) key, the public key must be stored in a KEY record in a zone served by the name server.

GSS-TSIG uses Kerberos credentials. Standard GSS-TSIG mode is switched on with the -g flag. A non-standards-compliant variant of GSS-TSIG used by Windows 2000 can be switched on with the -o flag.

Options¶

-4

This option sets use of IPv4 only.

-6

This option sets use of IPv6 only.

-d

This option sets debug mode, which provides tracing information about the update requests that are made and the replies received from the name server.

-D

This option sets extra debug mode.

-i

This option forces interactive mode, even when standard input is not a terminal.

-k keyfile

This option indicates the file containing the TSIG authentication key. Keyfiles may be in two formats: a single file containing a named.conf-format key statement, which may be generated automatically by ddns-confgen; or a pair of files whose names are of the format K{name}.+157.+{random}.key and K{name}.+157.+{random}.private, which can be generated by dnssec-keygen. The -k option can also be used to specify a SIG(0) key used to authenticate Dynamic DNS update requests. In this case, the key specified is not an HMAC-MD5 key.

-l

This option sets local-host only mode, which sets the server address to localhost (disabling the server so that the server address cannot be overridden). Connections to the local server use a TSIG key found in /var/run/named/session.key, which is automatically generated by named if any local primary zone has set update-policy to local. The location of this key file can be overridden with the -k option.

-L level

This option sets the logging debug level. If zero, logging is disabled.

-p port

This option sets the port to use for connections to a name server. The default is 53.

-P

This option prints the list of private BIND-specific resource record types whose format is understood by nsupdate. See also the -T option.

-r udpretries

This option sets the number of UDP retries. The default is 3. If zero, only one update request is made.

-t timeout

This option sets the maximum time an update request can take before it is aborted. The default is 300 seconds. If zero, the timeout is disabled.

-T

This option prints the list of IANA standard resource record types whose format is understood by nsupdate. nsupdate exits after the lists are printed. The -T option can be combined with the -P option.

Other types can be entered using TYPEXXXXX where XXXXX is the decimal value of the type with no leading zeros. The rdata, if present, is parsed using the UNKNOWN rdata format, (<backslash> <hash> <space> <length> <space> <hexstring>).

-u udptimeout

This option sets the UDP retry interval. The default is 3 seconds. If zero, the interval is computed from the timeout interval and number of UDP retries.

-v

This option specifies that TCP should be used even for small update requests. By default, nsupdate uses UDP to send update requests to the name server unless they are too large to fit in a UDP request, in which case TCP is used. TCP may be preferable when a batch of update requests is made.

-V

This option prints the version number and exits.

-y [hmac:]keyname:secret

This option sets the literal TSIG authentication key. keyname is the name of the key, and secret is the base64 encoded shared secret. hmac is the name of the key algorithm; valid choices are hmac-md5, hmac-sha1, hmac-sha224, hmac-sha256, hmac-sha384, or hmac-sha512. If hmac is not specified, the default is hmac-md5, or if MD5 was disabled, hmac-sha256.

NOTE: Use of the -y option is discouraged because the shared secret is supplied as a command-line argument in clear text. This may be visible in the output from ps1 or in a history file maintained by the user’s shell.

Input Format¶

nsupdate reads input from filename or standard input. Each command is supplied on exactly one line of input. Some commands are for administrative purposes; others are either update instructions or prerequisite checks on the contents of the zone. These checks set conditions that some name or set of resource records (RRset) either exists or is absent from the zone. These conditions must be met if the entire update request is to succeed. Updates are rejected if the tests for the prerequisite conditions fail.

Every update request consists of zero or more prerequisites and zero or more updates. This allows a suitably authenticated update request to proceed if some specified resource records are either present or missing from the zone. A blank input line (or the send command) causes the accumulated commands to be sent as one Dynamic DNS update request to the name server.

The command formats and their meanings are as follows:

server servername port: This command sends all dynamic update requests to the name server servername. When no server statement is provided, nsupdate sends updates to the primary server of the correct zone. The MNAME field of that zone’s SOA record identify the primary server for that zone. port is the port number on servername where the dynamic update requests are sent. If no port number is specified, the default DNS port number of 53 is used.
local address port: This command sends all dynamic update requests using the local address. When no local statement is provided, nsupdate sends updates using an address and port chosen by the system. port can also be used to force requests to come from a specific port. If no port number is specified, the system assigns one.
zone zonename: This command specifies that all updates are to be made to the zone zonename. If no zone statement is provided, nsupdate attempts to determine the correct zone to update based on the rest of the input.
class classname: This command specifies the default class. If no class is specified, the default class is IN.
ttl seconds: This command specifies the default time-to-live, in seconds, for records to be added. The value none clears the default TTL.
key hmac:keyname secret: This command specifies that all updates are to be TSIG-signed using the keyname-secret pair. If hmac is specified, it sets the signing algorithm in use. The default is hmac-md5; if MD5 was disabled, the default is hmac-sha256. The key command overrides any key specified on the command line via -y or -k.
gsstsig: This command uses GSS-TSIG to sign the updates. This is equivalent to specifying -g on the command line.
oldgsstsig: This command uses the Windows 2000 version of GSS-TSIG to sign the updates. This is equivalent to specifying -o on the command line.
realm [realm_name]: When using GSS-TSIG, this command specifies the use of realm_name rather than the default realm in krb5.conf. If no realm is specified, the saved realm is cleared.
check-names [yes_or_no]: This command turns on or off check-names processing on records to be added. Check-names has no effect on prerequisites or records to be deleted. By default check-names processing is on. If check-names processing fails, the record is not added to the UPDATE message.
prereq nxdomain domain-name: This command requires that no resource record of any type exist with the name domain-name.
prereq yxdomain domain-name: This command requires that domain-name exist (as at least one resource record, of any type).
prereq nxrrset domain-name class type: This command requires that no resource record exist of the specified type, class, and domain-name. If class is omitted, IN (Internet) is assumed.
prereq yxrrset domain-name class type: This command requires that a resource record of the specified type, class and domain-name exist. If class is omitted, IN (internet) is assumed.
prereq yxrrset domain-name class type data: With this command, the data from each set of prerequisites of this form sharing a common type, class, and domain-name are combined to form a set of RRs. This set of RRs must exactly match the set of RRs existing in the zone at the given type, class, and domain-name. The data are written in the standard text representation of the resource record’s RDATA.
update delete domain-name ttl class type data: This command deletes any resource records named domain-name. If type and data are provided, only matching resource records are removed. The Internet class is assumed if class is not supplied. The ttl is ignored, and is only allowed for compatibility.
update add domain-name ttl class type data: This command adds a new resource record with the specified ttl, class, and data.
show: This command displays the current message, containing all of the prerequisites and updates specified since the last send.
send: This command sends the current message. This is equivalent to entering a blank line.
answer: This command displays the answer.
debug: This command turns on debugging.
version: This command prints the version number.
help: This command prints a list of commands.

Lines beginning with a semicolon (;) are comments and are ignored.

Examples¶

The examples below show how nsupdate can be used to insert and delete resource records from the example.com zone. Notice that the input in each example contains a trailing blank line, so that a group of commands is sent as one dynamic update request to the primary name server for example.com.

# nsupdate
> update delete oldhost.example.com A
> update add newhost.example.com 86400 A 172.16.1.1
> send

Any A records for oldhost.example.com are deleted, and an A record for newhost.example.com with IP address 172.16.1.1 is added. The newly added record has a TTL of 1 day (86400 seconds).

# nsupdate
> prereq nxdomain nickname.example.com
> update add nickname.example.com 86400 CNAME somehost.example.com
> send

The prerequisite condition tells the name server to verify that there are no resource records of any type for nickname.example.com. If there are, the update request fails. If this name does not exist, a CNAME for it is added. This ensures that when the CNAME is added, it cannot conflict with the long-standing rule in RFC 1034 that a name must not exist as any other record type if it exists as a CNAME. (The rule has been updated for DNSSEC in RFC 2535 to allow CNAMEs to have RRSIG, DNSKEY, and NSEC records.)

Files¶

/etc/resolv.conf: Used to identify the default name server
/var/run/named/session.key: Sets the default TSIG key for use in local-only mode
K{name}.+157.+{random}.key: Base-64 encoding of the HMAC-MD5 key created by dnssec-keygen.
K{name}.+157.+{random}.private: Base-64 encoding of the HMAC-MD5 key created by dnssec-keygen.

Bugs¶

The TSIG key is redundantly stored in two separate files. This is a consequence of nsupdate using the DST library for its cryptographic operations, and may change in future releases.

pkcs11-destroy - destroy PKCS#11 objects

Synopsis¶

pkcs11-destroy [-m module] [-s slot] [-i ID] [-l label] [-p PIN] [-w seconds]

Description¶

pkcs11-destroy destroys keys stored in a PKCS#11 device, identified by their ID or label.

Matching keys are displayed before being destroyed. By default, there is a five-second delay to allow the user to interrupt the process before the destruction takes place.

Options¶

-m module: This option specifies the PKCS#11 provider module. This must be the full path to a shared library object implementing the PKCS#11 API for the device.
-s slot: This option opens the session with the given PKCS#11 slot. The default is slot 0.
-i ID: This option destroys keys with the given object ID.
-l label: This option destroys keys with the given label.
-p PIN: This option specifies the PIN for the device. If no PIN is provided on the command line, pkcs11-destroy prompts for it.
-w seconds: This option specifies how long, in seconds, to pause before carrying out key destruction. The default is 5 seconds. If set to 0, destruction is immediate.

pkcs11-keygen - generate keys on a PKCS#11 device¶

Synopsis¶

pkcs11-keygen [-a algorithm] [-b keysize] [-e] [-i id] [-m module] [-P] [-p PIN] [-q] [-S] [-s slot] label

Description¶

pkcs11-keygen causes a PKCS#11 device to generate a new key pair with the given label (which must be unique) and with keysize bits of prime.

Options¶

-a algorithm: This option specifies the key algorithm class: supported classes are RSA, DSA, DH, ECC, and ECX. In addition to these strings, the algorithm can be specified as a DNSSEC signing algorithm to be used with this key; for example, NSEC3RSASHA1 maps to RSA, ECDSAP256SHA256 maps to ECC, and ED25519 to ECX. The default class is RSA.
-b keysize: This option creates the key pair with keysize bits of prime. For ECC keys, the only valid values are 256 and 384, and the default is 256. For ECX keys, the only valid values are 256 and 456, and the default is 256.
-e: For RSA keys only, this option specifies use of a large exponent.
-i id: This option creates key objects with id. The ID is either an unsigned short 2-byte or an unsigned long 4-byte number.
-m module: This option specifies the PKCS#11 provider module. This must be the full path to a shared library object implementing the PKCS#11 API for the device.
-P: This option sets the new private key to be non-sensitive and extractable, and allows the private key data to be read from the PKCS#11 device. The default is for private keys to be sensitive and non-extractable.
-p PIN: This option specifies the PIN for the device. If no PIN is provided on the command line, pkcs11-keygen prompts for it.
-q: This option sets quiet mode, which suppresses unnecessary output.
-S: For Diffie-Hellman (DH) keys only, this option specifies use of a special prime of 768-, 1024-, or 1536-bit size and base (AKA generator) 2. If not specified, bit size defaults to 1024.
-s slot: This option opens the session with the given PKCS#11 slot. The default is slot 0.

pkcs11-list - list PKCS#11 objects¶

pkcs11-list [-P] [-m module] [-s slot] [-i ID ] [-l label] [-p PIN]

Description¶

pkcs11-list lists the PKCS#11 objects with ID or label or, by default, all objects. The object class, label, and ID are displayed for all keys. For private or secret keys, the extractability attribute is also displayed, as either true, false, or never.

Options¶

-P: This option lists only the public objects. (Note that on some PKCS#11 devices, all objects are private.)
-m module: This option specifies the PKCS#11 provider module. This must be the full path to a shared library object implementing the PKCS#11 API for the device.
-s slot: This option opens the session with the given PKCS#11 slot. The default is slot 0.
-i ID: This option lists only key objects with the given object ID.
-l label: This option lists only key objects with the given label.
-p PIN: This option specifies the PIN for the device. If no PIN is provided on the command line, pkcs11-list prompts for it.

pkcs11-tokens - list PKCS#11 available tokens¶

Synopsis¶

pkcs11-tokens [-m module] [-v]

Description¶

pkcs11-tokens lists the PKCS#11 available tokens with defaults from the slot/token scan performed at application initialization.

Options¶

-m module: This option specifies the PKCS#11 provider module. This must be the full path to a shared library object implementing the PKCS#11 API for the device.
-v: This option makes the PKCS#11 libisc initialization verbose.

rndc-confgen - rndc key generation tool¶

Synopsis¶

rndc-confgen [-a] [-A algorithm] [-b keysize] [-c keyfile] [-h] [-k keyname] [-p port] [-s address] [-t chrootdir] [-u user]

Description¶

rndc-confgen generates configuration files for rndc. It can be used as a convenient alternative to writing the rndc.conf file and the corresponding controls and key statements in named.conf by hand. Alternatively, it can be run with the -a option to set up a rndc.key file and avoid the need for a rndc.conf file and a controls statement altogether.

Options¶

-a

This option sets automatic rndc configuration, which creates a file rndc.key in /etc (or a different sysconfdir specified when BIND was built) that is read by both rndc and named on startup. The rndc.key file defines a default command channel and authentication key allowing rndc to communicate with named on the local host with no further configuration.

If a more elaborate configuration than that generated by rndc-confgen -a is required, for example if rndc is to be used remotely, run rndc-confgen without the -a option and set up rndc.conf and named.conf as directed.

-A algorithm

This option specifies the algorithm to use for the TSIG key. Available choices are: hmac-md5, hmac-sha1, hmac-sha224, hmac-sha256, hmac-sha384, and hmac-sha512. The default is hmac-sha256.

-b keysize

This option specifies the size of the authentication key in bits. The size must be between 1 and 512 bits; the default is the hash size.

-c keyfile

This option is used with the -a option to specify an alternate location for rndc.key.

-h

This option prints a short summary of the options and arguments to rndc-confgen.

-k keyname

This option specifies the key name of the rndc authentication key. This must be a valid domain name. The default is rndc-key.

-p port

This option specifies the command channel port where named listens for connections from rndc. The default is 953.

-s address

This option specifies the IP address where named listens for command-channel connections from rndc. The default is the loopback address 127.0.0.1.

-t chrootdir

This option is used with the -a option to specify a directory where named runs chrooted. An additional copy of the rndc.key is written relative to this directory, so that it is found by the chrooted named.

-u user

This option is used with the -a option to set the owner of the generated rndc.key file. If -t is also specified, only the file in the chroot area has its owner changed.

Examples¶

To allow rndc to be used with no manual configuration, run:

rndc-confgen -a

To print a sample rndc.conf file and the corresponding controls and key statements to be manually inserted into named.conf, run:

rndc-confgen

rndc.conf - rndc configuration file¶

Synopsis¶

rndc.conf

Description¶

rndc.conf is the configuration file for rndc, the BIND 9 name server control utility. This file has a similar structure and syntax to named.conf. Statements are enclosed in braces and terminated with a semi-colon. Clauses in the statements are also semi-colon terminated. The usual comment styles are supported:

C style: /* */

C++ style: // to end of line

Unix style: # to end of line

rndc.conf is much simpler than named.conf. The file uses three statements: an options statement, a server statement, and a key statement.

The options statement contains five clauses. The default-server clause is followed by the name or address of a name server. This host is used when no name server is given as an argument to rndc. The default-key clause is followed by the name of a key, which is identified by a key statement. If no keyid is provided on the rndc command line, and no key clause is found in a matching server statement, this default key is used to authenticate the server’s commands and responses. The default-port clause is followed by the port to connect to on the remote name server. If no port option is provided on the rndc command line, and no port clause is found in a matching server statement, this default port is used to connect. The default-source-address and default-source-address-v6 clauses can be used to set the IPv4 and IPv6 source addresses respectively.

After the server keyword, the server statement includes a string which is the hostname or address for a name server. The statement has three possible clauses: key, port, and addresses. The key name must match the name of a key statement in the file. The port number specifies the port to connect to. If an addresses clause is supplied, these addresses are used instead of the server name. Each address can take an optional port. If an source-address or source-address-v6 is supplied, it is used to specify the IPv4 and IPv6 source address, respectively.

The key statement begins with an identifying string, the name of the key. The statement has two clauses. algorithm identifies the authentication algorithm for rndc to use; currently only HMAC-MD5 (for compatibility), HMAC-SHA1, HMAC-SHA224, HMAC-SHA256 (default), HMAC-SHA384, and HMAC-SHA512 are supported. This is followed by a secret clause which contains the base-64 encoding of the algorithm’s authentication key. The base-64 string is enclosed in double quotes.

There are two common ways to generate the base-64 string for the secret. The BIND 9 program rndc-confgen can be used to generate a random key, or the mmencode program, also known as mimencode, can be used to generate a base-64 string from known input. mmencode does not ship with BIND 9 but is available on many systems. See the Example section for sample command lines for each.

Example¶

options {
  default-server  localhost;
  default-key     samplekey;
};

server localhost {
  key             samplekey;
};

server testserver {
  key     testkey;
  addresses   { localhost port 5353; };
};

key samplekey {
  algorithm       hmac-sha256;
  secret          "6FMfj43Osz4lyb24OIe2iGEz9lf1llJO+lz";
};

key testkey {
  algorithm   hmac-sha256;
  secret      "R3HI8P6BKw9ZwXwN3VZKuQ==";
};

In the above example, rndc by default uses the server at localhost (127.0.0.1) and the key called “samplekey”. Commands to the localhost server use the “samplekey” key, which must also be defined in the server’s configuration file with the same name and secret. The key statement indicates that “samplekey” uses the HMAC-SHA256 algorithm and its secret clause contains the base-64 encoding of the HMAC-SHA256 secret enclosed in double quotes.

If rndc -s testserver is used, then rndc connects to the server on localhost port 5353 using the key “testkey”.

To generate a random secret with rndc-confgen:

rndc-confgen

A complete rndc.conf file, including the randomly generated key, is written to the standard output. Commented-out key and controls statements for named.conf are also printed.

To generate a base-64 secret with mmencode:

echo "known plaintext for a secret" | mmencode

Name Server Configuration¶

The name server must be configured to accept rndc connections and to recognize the key specified in the rndc.conf file, using the controls statement in named.conf. See the sections on the controls statement in the BIND 9 Administrator Reference Manual for details.

rndc - name server control utility¶

Synopsis¶

rndc [-b source-address] [-c config-file] [-k key-file] [-s server] [-p port] [-q] [-r] [-V] [-y key_id] [[-4] | [-6]] {command}

Description¶

rndc controls the operation of a name server; it supersedes the ndc utility. If rndc is invoked with no command line options or arguments, it prints a short summary of the supported commands and the available options and their arguments.

rndc communicates with the name server over a TCP connection, sending commands authenticated with digital signatures. In the current versions of rndc and named, the only supported authentication algorithms are HMAC-MD5 (for compatibility), HMAC-SHA1, HMAC-SHA224, HMAC-SHA256 (default), HMAC-SHA384, and HMAC-SHA512. They use a shared secret on each end of the connection, which provides TSIG-style authentication for the command request and the name server’s response. All commands sent over the channel must be signed by a key_id known to the server.

rndc reads a configuration file to determine how to contact the name server and decide what algorithm and key it should use.

Options¶

-4: This option indicates use of IPv4 only.
-6: This option indicates use of IPv6 only.
-b source-address: This option indicates source-address as the source address for the connection to the server. Multiple instances are permitted, to allow setting of both the IPv4 and IPv6 source addresses.
-c config-file: This option indicates config-file as the configuration file instead of the default, /etc/rndc.conf.
-k key-file: This option indicates key-file as the key file instead of the default, /etc/rndc.key. The key in /etc/rndc.key is used to authenticate commands sent to the server if the config-file does not exist.
-s server: server is the name or address of the server which matches a server statement in the configuration file for rndc. If no server is supplied on the command line, the host named by the default-server clause in the options statement of the rndc configuration file is used.
-p port: This option instructs BIND 9 to send commands to TCP port port instead of its default control channel port, 953.
-q: This option sets quiet mode, where message text returned by the server is not printed unless there is an error.
-r: This option instructs rndc to print the result code returned by named after executing the requested command (e.g., ISC_R_SUCCESS, ISC_R_FAILURE, etc.).
-V: This option enables verbose logging.
-y key_id: This option indicates use of the key key_id from the configuration file. For control message validation to succeed, key_id must be known by named with the same algorithm and secret string. If no key_id is specified, rndc first looks for a key clause in the server statement of the server being used, or if no server statement is present for that host, then in the default-key clause of the options statement. Note that the configuration file contains shared secrets which are used to send authenticated control commands to name servers, and should therefore not have general read or write access.

Commands¶

A list of commands supported by rndc can be seen by running rndc without arguments.

Currently supported commands are:

addzone zone [class [view]] configuration

This command adds a zone while the server is running. This command requires the allow-new-zones option to be set to yes. The configuration string specified on the command line is the zone configuration text that would ordinarily be placed in named.conf.

The configuration is saved in a file called viewname.nzf (or, if named is compiled with liblmdb, an LMDB database file called viewname.nzd). viewname is the name of the view, unless the view name contains characters that are incompatible with use as a file name, in which case a cryptographic hash of the view name is used instead. When named is restarted, the file is loaded into the view configuration so that zones that were added can persist after a restart.

This sample addzone command adds the zone example.com to the default view:

rndc addzone example.com '{ type master; file "example.com.db"; };'

(Note the brackets around and semi-colon after the zone configuration text.)

See also rndc delzone and rndc modzone.

delzone [-clean] zone [class [view]]

This command deletes a zone while the server is running.

If the -clean argument is specified, the zone’s master file (and journal file, if any) are deleted along with the zone. Without the -clean option, zone files must be deleted manually. (If the zone is of type secondary or stub, the files needing to be removed are reported in the output of the rndc delzone command.)

If the zone was originally added via rndc addzone, then it is removed permanently. However, if it was originally configured in named.conf, then that original configuration remains in place; when the server is restarted or reconfigured, the zone is recreated. To remove it permanently, it must also be removed from named.conf.

See also rndc addzone and rndc modzone.

dnssec ( -status | -rollover -key id [-alg algorithm] [-when time] | -checkds [-key id [-alg algorithm]] [-when time] ( published | withdrawn )) zone [class [view]]

This command allows you to interact with the “dnssec-policy” of a given zone.

rndc dnssec -status show the DNSSEC signing state for the specified zone.

rndc dnssec -rollover allows you to schedule key rollover for a specific key (overriding the original key lifetime).

rndc dnssec -checkds will let named know that the DS for the given key has been seen published into or withdrawn from the parent. This is required in order to complete a KSK rollover. If the -key id argument is specified, look for the key with the given identifier, otherwise if there is only one key acting as a KSK in the zone, assume the DS of that key (if there are multiple keys with the same tag, use -alg algorithm to select the correct algorithm). The time that the DS has been published or withdrawn is set to now, unless otherwise specified with the argument -when time.

dnstap ( -reopen | -roll [number] )

This command closes and re-opens DNSTAP output files. rndc dnstap -reopen allows the output file to be renamed externally, so that named can truncate and re-open it. rndc dnstap -roll causes the output file to be rolled automatically, similar to log files. The most recent output file has “.0” appended to its name; the previous most recent output file is moved to “.1”, and so on. If number is specified, then the number of backup log files is limited to that number.

This command dumps the server’s caches (default) and/or zones to the dump file for the specified views. If no view is specified, all views are dumped. (See the dump-file option in the BIND 9 Administrator Reference Manual.)

flush

This command flushes the server’s cache.

flushname name [view]

This command flushes the given name from the view’s DNS cache and, if applicable, from the view’s nameserver address database, bad server cache, and SERVFAIL cache.

flushtree name [view]

This command flushes the given name, and all of its subdomains, from the view’s DNS cache, address database, bad server cache, and SERVFAIL cache.

freeze [zone [class [view]]]

This command suspends updates to a dynamic zone. If no zone is specified, then all zones are suspended. This allows manual edits to be made to a zone normally updated by dynamic update, and causes changes in the journal file to be synced into the master file. All dynamic update attempts are refused while the zone is frozen.

Limitations¶

There is currently no way to provide the shared secret for a key_id without using the configuration file.

Several error messages could be clearer.

Manual Pages¶

arpaname - translate IP addresses to the corresponding ARPA names¶

Synopsis¶

Description¶

See Also¶

ddns-confgen - ddns key generation tool¶

Synopsis¶

Description¶

Options¶

See Also¶

delv - DNS lookup and validation utility¶

Synopsis¶

Description¶

Simple Usage¶

Options¶

Query Options¶

Files¶

See Also¶

dig - DNS lookup utility¶

Synopsis¶

Description¶

Simple Usage¶

Options¶

Query Options¶

Multiple Queries¶

IDN Support¶

Return Codes¶

Files¶

See Also¶

Bugs¶

dnssec-cds - change DS records for a child zone based on CDS/CDNSKEY¶

Synopsis¶

Description¶

Options¶

Exit Status¶

Examples¶

See Also¶

dnssec-dsfromkey - DNSSEC DS RR generation tool¶

Synopsis¶

Description¶

Options¶

Example¶

Files¶

Caveat¶

See Also¶

dnssec-importkey - import DNSKEY records from external systems so they can be managed¶

Synopsis¶

Description¶

Options¶

Timing Options¶

Files¶

See Also¶

dnssec-checkds - DNSSEC delegation consistency checking tool¶

Synopsis¶

Description¶

Options¶

See Also¶

dnssec-coverage - checks future DNSKEY coverage for a zone¶

Synopsis¶

Description¶

Options¶

See Also¶

dnssec-keymgr - Ensures correct DNSKEY coverage based on a defined policy¶

Synopsis¶

Description¶

Options¶

Policy Configuration¶

Remaining Work¶

See Also¶

dnssec-keyfromlabel - DNSSEC key generation tool¶

Synopsis¶

Description¶

Options¶

Timing Options¶

Generated Key Files¶

See Also¶

dnssec-keygen: DNSSEC key generation tool¶

Synopsis¶

Description¶

Options¶