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.
See Also¶
BIND 9 Administrator Reference Manual.
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:
serveris 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
serverargument is a hostname,delvresolves that name before querying that name server (note, however, that this initial lookup is not validated by DNSSEC).If no
serverargument is provided,delvconsults/etc/resolv.conf; if an address is found there, it queries the name server at that address. If either of the-4or-6options is in use, then only addresses for the corresponding transport are tried. If no usable addresses are found,delvsends queries to the localhost addresses (127.0.0.1 for IPv4, ::1 for IPv6).nameis the domain name to be looked up.
typeindicates what type of query is required - ANY, A, MX, etc.
typecan be any valid query type. If notypeargument is supplied,delvperforms a lookup for an A record.
Options¶
-a anchor-fileThis 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=NAMEoptions.Note: When reading the trust anchor file,
delvtreatstrust-anchors,initial-key, andstatic-keyidentically. That is, for a managed key, it is the initial key that is trusted; RFC 5011 key management is not supported.delvdoes not consult the managed-keys database maintained bynamed, which means that if either of the keys in/etc/bind.keysis revoked and rolled over,/etc/bind.keysmust be updated to use DNSSEC validation indelv.-b addressThis 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, or0.0.0.0, or::. An optional source port may be specified by appending#<port>-c classThis option sets the query class for the requested data. Currently, only class “IN” is supported in
delvand any other value is ignored.-d levelThis option sets the systemwide debug level to
level. The allowed range is from 0 to 99. The default is 0 (no debugging). Debugging traces fromdelvbecome more verbose as the debug level increases. See the+mtrace,+rtrace, and+vtraceoptions below for additional debugging details.-hThis option displays the
delvhelp usage output and exits.-iThis 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
delvto time out. When it is necessary to examine invalid data to debug a DNSSEC problem, usedig +cd.)-mThis 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 nameThis option sets the query name to
name. While the query name can be specified without using the-qoption, 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 typeThis 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
-xoption is supplied to indicate a reverse lookup, in which case it is “PTR”.-vThis option prints the
delvversion and exits.-x addrThis option performs a reverse lookup, mapping an address to a name.
addris an IPv4 address in dotted-decimal notation, or a colon-delimited IPv6 address. When-xis used, there is no need to provide thenameortypearguments;delvautomatically performs a lookup for a name like11.12.13.10.in-addr.arpaand sets the query type to PTR. IPv6 addresses are looked up using nibble format under the IP6.ARPA domain.-4This option forces
delvto only use IPv4.-6This option forces
delvto 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]cdflagThis 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, whichdelvcan then validate internally and report the errors in detail.+[no]classThis option controls whether to display the CLASS when printing a record. The default is to display the CLASS.
+[no]ttlThis option controls whether to display the TTL when printing a record. The default is to display the TTL.
+[no]rtraceThis option toggles resolver fetch logging. This reports the name and type of each query sent by
delvin 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
-doption produces the same output, but affects other logging categories as well.+[no]mtraceThis option toggles message logging. This produces a detailed dump of the responses received by
delvin 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
-doption produces the same output, but affects other logging categories as well.+[no]vtraceThis 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
-doption produces the same output, but affects other logging categories as well.+[no]shortThis option toggles between verbose and terse answers. The default is to print the answer in a verbose form.
+[no]commentsThis option toggles the display of comment lines in the output. The default is to print comments.
+[no]rrcommentsThis 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]cryptoThis 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]trustThis 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
Wcharacters (whereWis rounded up to the nearest multiple of 4).+nosplitor+split=0causes fields not to be split at all. The default is 56 characters, or 44 characters when multiline mode is active.+[no]allThis option sets or clears the display options
+[no]comments,+[no]rrcomments, and+[no]trustas a group.+[no]multilineThis 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
delvoutput.+[no]dnssecThis option indicates whether to display RRSIG records in the
delvoutput. The default is to do so. Note that (unlike indig) 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-ior+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
-amust be used to specify a file containing the key.+[no]tcpThis option controls whether to use TCP when sending queries. The default is to use UDP unless a truncated response has been received.
+[no]unknownformatThis 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]yamlThis option prints response data in YAML format.
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:
serveris 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
serverargument is a hostname,digresolves that name before querying that name server.If no
serverargument is provided,digconsults/etc/resolv.conf; if an address is found there, it queries the name server at that address. If either of the-4or-6options are in use, then only addresses for the corresponding transport are tried. If no usable addresses are found,digsends the query to the local host. The reply from the name server that responds is displayed.nameis the name of the resource record that is to be looked up.
typeindicates what type of query is required - ANY, A, MX, SIG, etc.
typecan be any valid query type. If notypeargument is supplied,digperforms a lookup for an A record.
Options¶
-4This option indicates that only IPv4 should be used.
-6This option indicates that only IPv6 should be used.
-b address[#port]This option sets the source IP address of the query. The
addressmust 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 classThis option sets the query class. The default
classis IN; other classes are HS for Hesiod records or CH for Chaosnet records.-f fileThis option sets batch mode, in which
digreads a list of lookup requests to process from the givenfile. Each line in the file should be organized in the same way it would be presented as a query todigusing the command-line interface.-k keyfileThis option tells
namedto sign queries using TSIG using a key read from the given file. Key files can be generated usingtsig-keygen. When using TSIG authentication withdig, the name server that is queried needs to know the key and algorithm that is being used. In BIND, this is done by providing appropriatekeyandserverstatements innamed.conf.-mThis option enables memory usage debugging.
-p portThis 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 nameThis option specifies the domain name to query. This is useful to distinguish the
namefrom other arguments.-rThis option indicates that options from
${HOME}/.digrcshould not be read. This is useful for scripts that need predictable behavior.-t typeThis 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
NSorAAAA). The default query type isA, unless the-xoption 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 thetypetoixfr=N. The incremental zone transfer contains all changes made to the zone since the serial number in the zone’s SOA record wasN.All resource record types can be expressed as
TYPEnn, wherennis 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.-uThis option indicates that print query times should be provided in microseconds instead of milliseconds.
-vThis option prints the version number and exits.
-x addrThis option sets simplified reverse lookups, for mapping addresses to names. The
addris an IPv4 address in dotted-decimal notation, or a colon-delimited IPv6 address. When the-xoption is used, there is no need to provide thename,class, andtypearguments.digautomatically performs a lookup for a name like94.2.0.192.in-addr.arpaand 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:secretThis option signs queries using TSIG with the given authentication key.
keynameis the name of the key, andsecretis the base64-encoded shared secret.hmacis the name of the key algorithm; valid choices arehmac-md5,hmac-sha1,hmac-sha224,hmac-sha256,hmac-sha384, orhmac-sha512. Ifhmacis not specified, the default ishmac-md5; if MD5 was disabled, the default ishmac-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]aaflagThis option is a synonym for
+[no]aaonly.+[no]aaonlyThis option sets the
aaflag in the query.+[no]additionalThis option displays [or does not display] the additional section of a reply. The default is to display it.
+[no]adflagThis 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=1indicates that all records have been validated as secure and the answer is not from a OPT-OUT range.AD=0indicates that some part of the answer was insecure or not validated. This bit is set by default.+[no]allThis option sets or clears all display flags.
+[no]answerThis option displays [or does not display] the answer section of a reply. The default is to display it.
+[no]authorityThis option displays [or does not display] the authority section of a reply. The default is to display it.
+[no]badcookieThis option retries the lookup with a new server cookie if a BADCOOKIE response is received.
+[no]besteffortThis 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
Bbytes. The maximum and minimum sizes of this buffer are 65535 and 0, respectively.+bufsizerestores the default buffer size.+[no]cdflagThis 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]classThis option displays [or does not display] the CLASS when printing the record.
+[no]cmdThis option toggles the printing of the initial comment in the output, identifying the version of
digand 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]commentsThis 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.+cookieis also set when+traceis set to better emulate the default queries from a nameserver.+[no]cryptoThis 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]defnameThis option, which is deprecated, is treated as a synonym for
+[no]search.+[no]dns64prefixLookup IPV4ONLY.ARPA AAAA and print any DNS64 prefixes found.
+[no]dnssecThis 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=somenameThis option sets the search list to contain the single domain
somename, as if specified in adomaindirective in/etc/resolv.conf, and enables search list processing as if the+searchoption were given.+dscp=valueThis 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.
+noednsclears 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]ednsnegotiationThis 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
codeand an optional payload ofvalueas a hexadecimal string.codecan be either an EDNS option name (for example,NSIDorECS) or an arbitrary numeric value.+noednsoptclears the EDNS options to be sent.+[no]expireThis option sends an EDNS Expire option.
+[no]failThis option indicates that
namedshould 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-onlyThis 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]https[=value]This option indicates whether to use DNS-over-HTTPS (DoH) when querying name servers. When this option is in use, the port number defaults to 443. The HTTP POST request mode is used when sending the query.
If
valueis specified, it will be used as the HTTP endpoint in the query URI; the default is/dns-query. So, for example,dig @example.com +httpswill use the URIhttps://example.com/dns-query.+[no]https-get[=value]Similar to
+https, except that the HTTP GET request mode is used when sending the query.+[no]https-post[=value]Same as
+https.+[no]http-plain[=value]Similar to
+https, except that HTTP queries will be sent over a non-encrypted channel. When this option is in use, the port number defaults to 80 and the HTTP request mode is POST.+[no]http-plain-get[=value]Similar to
+http-plain, except that the HTTP request mode is GET.+[no]http-plain-post[=value]Same as
+http-plain.+[no]identifyThis option shows [or does not show] the IP address and port number that supplied the answer, when the
+shortoption 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]idninThis option processes [or does not process] IDN domain names on input. This requires
IDN SUPPORTto 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
digoutput is redirected to files, pipes, and other non-tty file descriptors.+[no]idnoutThis option converts [or does not convert] puny code on output. This requires
IDN SUPPORTto 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
digoutput is redirected to files, pipes, and other non-tty file descriptors.+[no]ignoreThis option ignores [or does not ignore] truncation in UDP responses instead of retrying with TCP. By default, TCP retries are performed.
+[no]keepaliveThis option sends [or does not send] an EDNS Keepalive option.
+[no]keepopenThis 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]mappedThis option allows [or does not allow] mapped IPv4-over-IPv6 addresses to be used. The default is
+mapped.+[no]multilineThis 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
digoutput.+ndots=DThis option sets the number of dots (
D) that must appear innamefor it to be considered absolute. The default value is that defined using thendotsstatement in/etc/resolv.conf, or 1 if nondotsstatement is present. Names with fewer dots are interpreted as relative names, and are searched for in the domains listed in thesearchordomaindirective in/etc/resolv.confif+searchis set.+[no]nsidWhen enabled, this option includes an EDNS name server ID request when sending a query.
+[no]nssearchWhen this option is set,
digattempts 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]onesoaWhen 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=valueWhen enabled, this option sets (restores) the DNS message opcode to the specified value. The default value is QUERY (0).
+padding=valueThis option pads the size of the query packet using the EDNS Padding option to blocks of
valuebytes. For example,+padding=32causes 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.+qid=valueThis option specifies the query ID to use when sending queries.
+[no]qrThis option toggles the display of the query message as it is sent. By default, the query is not printed.
+[no]questionThis 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]raflagThis 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]rdflagThis option is a synonym for
+[no]recurse.+[no]recurseThis option toggles the setting of the RD (recursion desired) bit in the query. This bit is set by default, which means
dignormally sends recursive queries. Recursion is automatically disabled when the+nssearchor+tracequery option is used.+retry=TThis option sets the number of times to retry UDP and TCP queries to server to
Tinstead of the default, 2. Unlike+tries, this does not include the initial query.+[no]rrcommentsThis 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]searchThis 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.ndotsfromresolv.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]shortThis 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]showsearchThis option performs [or does not perform] a search showing intermediate results.
+[no]sigchaseThis feature is now obsolete and has been removed; use
delvinstead.+split=WThis option splits long hex- or base64-formatted fields in resource records into chunks of
Wcharacters (whereWis rounded up to the nearest multiple of 4).+nosplitor+split=0causes fields not to be split at all. The default is 56 characters, or 44 characters when multiline mode is active.+[no]statsThis 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 simplydig +subnet=0for 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]tcflagThis 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]tcpThis option indicates whether to use TCP when querying name servers. The default behavior is to use UDP unless a type
anyorixfr=Nquery is requested, in which case the default is TCP. AXFR queries always use TCP.+timeout=TThis option sets the timeout for a query to
Tseconds. The default timeout is 5 seconds. An attempt to setTto less than 1 is silently set to 1.+[no]tlsThis option indicates whether to use DNS-over-TLS (DoT) when querying name servers. When this option is in use, the port number defaults to 853.
+[no]topdownThis feature is related to
dig +sigchase, which is obsolete and has been removed. Usedelvinstead.+[no]traceThis 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,
digmakes 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
@serveris also specified, it affects only the initial query for the root zone name servers.+dnssecis also set when+traceis set, to better emulate the default queries from a name server.+tries=TThis option sets the number of times to try UDP and TCP queries to server to
Tinstead of the default, 3. IfTis 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; usedelvinstead.+[no]ttlidThis option displays [or does not display] the TTL when printing the record.
+[no]ttlunitsThis option displays [or does not display] the TTL in friendly human-readable time units of
s,m,h,d, andw, representing seconds, minutes, hours, days, and weeks. This implies+ttlid.+[no]unknownformatThis 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]vcThis option uses [or does not use] TCP when querying name servers. This alternate syntax to
+[no]tcpis provided for backwards compatibility. Thevcstands for “virtual circuit.”+[no]yamlWhen enabled, this option prints the responses (and, if
+qris in use, also the outgoing queries) in a detailed YAML format.+[no]zflagThis 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.
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 algorithmThis 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 classThis option specifies the DNS class of the zones.
-DThis 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 pathThis 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-cdslooks for adsset-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-soption.-f child-fileThis 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.
-iextensionThis option updates the
dsset-file in place, instead of writing DS records to the standard output.There must be no space between the
-iand the extension. If no extension is provided, the olddsset-is discarded. If an extension is present, a backup of the olddsset-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-timeThis 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 withnow+N.If no start-time is specified, the modification time of the
dsset-file is used.-T ttlThis 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.
-uThis option writes an
nsupdatescript 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-Toption, or using thensupdatettlcommand.-VThis option prints version information.
-v levelThis option sets the debugging level. Level 1 is intended to be usefully verbose for general users; higher levels are intended for developers.
domainThis 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¶
-1This option is an abbreviation for
-a SHA1.-2This option is an abbreviation for
-a SHA-256.-a algorithmThis 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.
-AThis 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
-fzone file mode.-c classThis option specifies the DNS class; the default is IN. This option is only useful in
-skeyset or-fzone file mode.-CThis option generates CDS records rather than DS records.
-f fileThis option sets zone file mode, in which the final dnsname argument of
dnssec-dsfromkeyis the DNS domain name of a zone whose master file can be read fromfile. If the zone name is the same asfile, then it may be omitted.If
fileis-, then the zone data is read from the standard input. This makes it possible to use the output of thedigcommand as input, as in:dig dnskey example.com | dnssec-dsfromkey -f - example.com-hThis option prints usage information.
-K directoryThis option tells BIND 9 to look for key files or
keyset-files indirectory.-sThis option enables keyset mode, in which the final dnsname argument from
dnssec-dsfromkeyis the DNS domain name used to locate akeyset-file.-T TTLThis option specifies the TTL of the DS records. By default the TTL is omitted.
-v levelThis option sets the debugging level.
-VThis 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 filenameThis 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 asfilename, then it may be omitted.If
filenameis set to"-", then the zone data is read from the standard input.-K directoryThis option sets the directory in which the key files are to reside.
-L ttlThis 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
0ornoneremoves it from the key.-hThis option emits a usage message and exits.
-v levelThis option sets the debugging level.
-VThis 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/offsetThis 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/offsetThis option sets the date on which CDS and CDNSKEY records that match this key are to be published to the zone.
-D date/offsetThis 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/offsetThis 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-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 algorithmThis option selects the cryptographic algorithm. The value of
algorithmmust be one of RSASHA1, NSEC3RSASHA1, RSASHA256, RSASHA512, ECDSAP256SHA256, ECDSAP384SHA384, ED25519, or ED448.If no algorithm is specified, RSASHA1 is used by default unless the
-3option is specified, in which case NSEC3RSASHA1 is used instead. (If-3is 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
-3option, then NSEC3RSASHA1 is used instead.Since BIND 9.12.0, this option is mandatory except when using the
-Soption, which copies the algorithm from the predecessory key. Previously, the default for newly generated keys was RSASHA1.-3This 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 RSASHA1specifies the NSEC3RSASHA1 algorithm.-E engineThis 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 labelThis 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 includetoken, which identifies the HSM;object, which identifies the key; andpin-source, which identifies a file from which the HSM’s PIN code can be obtained. The label is stored in the on-diskprivatefile.If the label contains a
pin-sourcefield, 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 nametypeThis option specifies the owner type of the key. The value of
nametypemust 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.-CThis option enables compatibility mode, which generates an old-style key, without any metadata. By default,
dnssec-keyfromlabelincludes 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-Coption suppresses them.-c classThis option indicates that the DNS record containing the key should have the specified class. If not specified, class IN is used.
-f flagThis option sets the specified flag in the
flagfield of the KEY/DNSKEY record. The only recognized flags are KSK (Key-Signing Key) and REVOKE.-GThis option generates a key, but does not publish it or sign with it. This option is incompatible with
-Pand-A.-hThis option prints a short summary of the options and arguments to
dnssec-keyfromlabel.-K directoryThis option sets the directory in which the key files are to be written.
-kThis option generates KEY records rather than DNSKEY records.
-LttlThis 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
0ornoneremoves it.-p protocolThis 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 keyThis 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 typeThis option indicates the type of the key.
typemust 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 levelThis option sets the debugging level.
-VThis option prints version information.
-yThis 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/offsetThis 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
-Goption has not been used, the default is the current date.-P sync date/offsetThis option sets the date on which CDS and CDNSKEY records that match this key are to be published to the zone.
-A date/offsetThis 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
-Goption has not been used, the default is the current date.-R date/offsetThis 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/offsetThis 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/offsetThis 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/offsetThis option sets the date on which the CDS and CDNSKEY records that match this key are to be deleted.
-i intervalThis 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, ormi, 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.
nnnnis the key name.aaais the numeric representation of the algorithm.iiiiiis 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.
Options¶
-3This 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 RSASHA1specifies the NSEC3RSASHA1 algorithm.-a algorithmThis option selects the cryptographic algorithm. For DNSSEC keys, the value of
algorithmmust 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 KEYoption 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
-3option, NSEC3RSASHA1 is used instead.This parameter must be specified except when using the
-Soption, 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-keygento generate TSIG keys.-b keysizeThis 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.-CThis option enables compatibility mode, which generates an old-style key, without any timing metadata. By default,
dnssec-keygenincludes 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-Coption suppresses them.-c classThis option indicates that the DNS record containing the key should have the specified class. If not specified, class IN is used.
-d bitsThis 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 engineThis 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 flagThis 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.
-GThis option generates a key, but does not publish it or sign with it. This option is incompatible with
-Pand-A.-g generatorThis 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.
-hThis option prints a short summary of the options and arguments to
dnssec-keygen.-K directoryThis option sets the directory in which the key files are to be written.
-k policyThis option creates keys for a specific
dnssec-policy. If a policy uses multiple keys,dnssec-keygengenerates multiple keys. This also creates a “.state” file to keep track of the key state.This option creates keys according to the
dnssec-policyconfiguration, hence it cannot be used at the same time as many of the other options thatdnssec-keygenprovides.-L ttlThis 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
0ornoneis the same as leaving it unset.-l fileThis option provides a configuration file that contains a
dnssec-policystatement (matching the policy set with-k).-n nametypeThis option specifies the owner type of the key. The value of
nametypemust 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 protocolThis 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.-qThis option sets quiet mode, which suppresses unnecessary output, including progress indication. Without this option, when
dnssec-keygenis run interactively to generate an RSA or DSA key pair, it prints a string of symbols tostderrindicating 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 keyThis 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 strengthThis 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 rrtypeThis option specifies the resource record type to use for the key.
rrtypemust 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 typeThis option indicates the type of the key for use with
-T KEY.typemust 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.-VThis option prints version information.
-v levelThis 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/offsetThis 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
-Goption has not been used, the default is the current date.-P sync date/offsetThis option sets the date on which CDS and CDNSKEY records that match this key are to be published to the zone.
-A date/offsetThis 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
-Goption has not been used, the default is the current date. If set, and-Pis not set, the publication date is set to the activation date minus the prepublication interval.-R date/offsetThis 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/offsetThis 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/offsetThis 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/offsetThis option sets the date on which the CDS and CDNSKEY records that match this key are to be deleted.
-i intervalThis 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, ormi, 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.
nnnnis the key name.aaais the numeric representation of the algorithm.iiiiiis 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¶
-hThis option emits a usage message and exits.
-K directoryThis option sets the directory in which the key files are to reside.
-rThis option indicates to remove the original keyset files after writing the new keyset files.
-v levelThis option sets the debugging level.
-VThis option prints version information.
-E engineThis 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.-fThis option indicates a forced overwrite and causes
dnssec-revoketo write the new key pair, even if a file already exists matching the algorithm and key ID of the revoked key.-RThis 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¶
-fThis option forces an update of an old-format key with no metadata fields. Without this option,
dnssec-settimefails 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 directoryThis option sets the directory in which the key files are to reside.
-L ttlThis 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
0ornoneremoves it from the key.-hThis option emits a usage message and exits.
-VThis option prints version information.
-v levelThis option sets the debugging level.
-E engineThis 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/offsetThis 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/offsetThis option sets the date on which DS records that match this key have been seen in the parent zone.
-P sync date/offsetThis option sets the date on which CDS and CDNSKEY records that match this key are to be published to the zone.
-A date/offsetThis 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/offsetThis 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/offsetThis 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/offsetThis 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/offsetThis option sets the date on which the DS records that match this key have been seen removed from the parent zone.
-D sync date/offsetThis option sets the date on which the CDS and CDNSKEY records that match this key are to be deleted.
-S predecessor keyThis 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 intervalThis 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, ormi, 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.
-sThis option indicates that when setting key timing data, the state file should also be updated.
-g stateThis option sets the goal state for this key. Must be HIDDEN or OMNIPRESENT.
-d state date/offsetThis option sets the DS state for this key as of the specified date, offset from the current date.
-k state date/offsetThis option sets the DNSKEY state for this key as of the specified date, offset from the current date.
-r state date/offsetThis option sets the RRSIG (KSK) state for this key as of the specified date, offset from the current date.
-z state date/offsetThis 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.
-uThis option indicates that times should be printed in Unix epoch format.
-p C/P/Pds/Psync/A/R/I/D/Dds/Dsync/allThis option prints a specific metadata value or set of metadata values. The
-poption may be followed by one or more of the following letters or strings to indicate which value or values to print:Cfor the creation date,Pfor the publication date,Pds` for the DS publication date, ``Psyncfor the CDS and CDNSKEY publication date,Afor the activation date,Rfor the revocation date,Ifor the inactivation date,Dfor the deletion date,Ddsfor the DS deletion date, andDsyncfor the CDS and CDNSKEY deletion date. To print all of the metadata, useall.
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¶
-aThis option verifies all generated signatures.
-c classThis option specifies the DNS class of the zone.
-CThis option sets compatibility mode, in which a
keyset-zonenamefile is generated in addition todsset-zonenamewhen signing a zone, for use by older versions ofdnssec-signzone.-d directoryThis option indicates the directory where BIND 9 should look for
dsset-orkeyset-files.-DThis 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 engineThis 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.-gThis option indicates that DS records for child zones should be generated from a
dsset-orkeyset-file. Existing DS records are removed.-K directoryThis option specifies the directory to search for DNSSEC keys. If not specified, it defaults to the current directory.
-k keyThis 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 maxttlThis option sets the maximum TTL for the signed zone. Any TTL higher than
maxttlin the input zone is reduced tomaxttlin 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 matchingmax-zone-ttlinnamed.conf. (Note: This option is incompatible with-D, because it modifies non-DNSSEC data in the output zone.)-s start-timeThis 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 nostart-timeis specified, the current time minus 1 hour (to allow for clock skew) is used.-e end-timeThis 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 withnow+N. If noend-timeis specified, 30 days from the start time is the default.end-timemust be later thanstart-time.-X extended end-timeThis 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 withnow+N. If noextended end-timeis specified, the value ofend-timeis used as the default. (end-time, in turn, defaults to 30 days from the start time.)extended end-timemust be later thanstart-time.-f output-fileThis option indicates the name of the output file containing the signed zone. The default is to append
.signedto the input filename. Ifoutput-fileis set to-, then the signed zone is written to the standard output, with a default output format offull.-hThis option prints a short summary of the options and arguments to
dnssec-signzone.-VThis option prints version information.
-i intervalThis option indicates that, when a previously signed zone is passed as input, records may be re-signed. The
intervaloption 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-timenorstart-timeis specified,dnssec-signzonegenerates 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-formatThis option sets the format of the input zone file. Possible formats are
text(the default),raw, andmap. 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 jitterWhen 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
jitteroption 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 serialWhen writing a signed zone to “raw” or “map” format, this option sets the “source serial” value in the header to the specified
serialnumber. (This is expected to be used primarily for testing purposes.)-n ncpusThis option specifies the number of threads to use. By default, one thread is started for each detected CPU.
-N soa-serial-formatThis option sets the SOA serial number format of the signed zone. Possible formats are
keep(the default),increment,unixtime, anddate.- 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 originThis option sets the zone origin. If not specified, the name of the zone file is assumed to be the origin.
-O output-formatThis 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; andmap,raw, andraw=N, which store the zone in binary formats for rapid loading bynamed.raw=Nspecifies the format version of the raw zone file: if N is 0, the raw file can be read by any version ofnamed; if N is 1, the file can be read by release 9.9.0 or higher. The default is 1.-PThis 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.
-QThis 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
-Qoption forcesdnssec-signzoneto 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”).-qThis option enables quiet mode, which suppresses unnecessary output. Without this option, when
dnssec-signzoneis 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.-RThis option removes signatures from keys that are no longer published.
This option is similar to
-Q, except it forcesdnssec-signzoneto 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”).-SThis option enables smart signing, which instructs
dnssec-signzoneto 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 ttlThis 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.-tThis option prints statistics at completion.
-uThis 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-signzoneretains the existing chain when re-signing.-v levelThis option sets the debugging level.
-xThis 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 innamed.)-zThis 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 innamed.)-3 saltThis 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 iterationsThis option indicates that, when generating an NSEC3 chain, BIND 9 should use this many iterations. The default is 10.
-AThis 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-uoption to modify an NSEC3 chain which previously had OPTOUT set.zonefileThis option sets the file containing the zone to be signed.
keyThis 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 classThis option specifies the DNS class of the zone.
-E engineThis 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-formatThis option sets the format of the input zone file. Possible formats are
text(the default) andraw. 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 originThis option indicates the zone origin. If not specified, the name of the zone file is assumed to be the origin.
-v levelThis option sets the debugging level.
-VThis option prints version information.
-qThis option sets quiet mode, which suppresses output. Without this option, when
dnssec-verifyis 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.-xThis 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
-xoption indnssec-signzone.-zThis 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
-zoption indnssec-signzone.zonefileThis 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¶
-mThis option indicates trace memory allocations, and is used for debugging memory leaks.
-pThis option prints the text form of the DNS message that was encapsulated in the
dnstapframe, after printing thednstapdata.-xThis option prints a hex dump of the wire form of the DNS message that was encapsulated in the
dnstapframe, after printing thednstapdata.-yThis option prints
dnstapdata in a detailed YAML format.
See Also¶
named(8), rndc(8), BIND 9 Administrator Reference Manual.
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-aaaaThis option specifies a list of client addresses for which AAAA filtering is to be applied. The default is
any.filter-aaaa-on-v4If set to
yes, this option indicates that the DNS client is at an IPv4 address, infilter-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-v6This 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 toyes.
See Also¶
BIND 9 Administrator Reference Manual.
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¶
-4This option specifies that only IPv4 should be used for query transport. See also the
-6option.-6This option specifies that only IPv6 should be used for query transport. See also the
-4option.-aThe
-a(“all”) option is normally equivalent to-v -t ANY. It also affects the behavior of the-llist zone option.-AThe
-A(“almost all”) option is equivalent to-a, except that RRSIG, NSEC, and NSEC3 records are omitted from the output.-c classThis 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).
-CThis option indicates that
namedshould check consistency, meaning thathostqueries the SOA records for zonenamefrom 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.-dThis option prints debugging traces, and is equivalent to the
-vverbose option.-lThis option tells
named` to list the zone, meaning the ``hostcommand performs a zone transfer of zonenameand prints out the NS, PTR, and address records (A/AAAA).Together, the
-l -aoptions print all records in the zone.-N ndotsThis option specifies the number of dots (
ndots) that have to be innamefor it to be considered absolute. The default value is that defined using thendotsstatement in/etc/resolv.conf, or 1 if nondotsstatement is present. Names with fewer dots are interpreted as relative names, and are searched for in the domains listed in thesearchordomaindirective in/etc/resolv.conf.-p portThis option specifies the port to query on the server. The default is 53.
-rThis 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-roption enableshostto 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 numberThis option specifies the number of retries for UDP queries. If
numberis negative or zero, the number of retries is silently set to 1. The default value is 1, or the value of theattemptsoption in/etc/resolv.conf, if set.-sThis option tells
namednot 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 typeThis option specifies the query type. The
typeargument can be any recognized query type: CNAME, NS, SOA, TXT, DNSKEY, AXFR, etc.When no query type is specified,
hostautomatically selects an appropriate query type. By default, it looks for A, AAAA, and MX records. If the-Coption is given, queries are made for SOA records. Ifnameis a dotted-decimal IPv4 address or colon-delimited IPv6 address,hostqueries 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;-UThis option specifies TCP or UDP. By default,
hostuses UDP when making queries; the-Toption 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. TypeANYqueries default to TCP, but can be forced to use UDP initially via-U.-m flagThis option sets memory usage debugging: the flag can be
record,usage, ortrace. The-moption can be specified more than once to set multiple flags.-vThis option sets verbose output, and is equivalent to the
-ddebug option. Verbose output can also be enabled by setting thedebugoption in/etc/resolv.conf.-VThis option prints the version number and exits.
-wThis option sets “wait forever”: the query timeout is set to the maximum possible. See also the
-Woption.-W waitThis options sets the length of the wait timeout, indicating that
namedshould wait for up towaitseconds for a reply. Ifwaitis less than 1, the wait interval is set to 1 second.By default,
hostwaits for 5 seconds for UDP responses and 10 seconds for TCP connections. These defaults can be overridden by thetimeoutoption in/etc/resolv.conf.See also the
-woption.
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
See Also¶
dig(1), named(8).
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¶
-fThis option makes
mdigoperate in batch mode by reading a list of lookup requests to process from the filefilename. 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 tomdigusing the command-line interface.-hThis option causes
mdigto print detailed help information, with the full list of options, and exit.-vThis option causes
mdigto print the version number and exit.
Global Options¶
-4This option forces
mdigto only use IPv4 query transport.-6This option forces
mdigto only use IPv6 query transport.-b addressThis 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>”-mThis 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 thatmdigsends 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]additionalThis option displays [or does not display] the additional section of a reply. The default is to display it.
+[no]allThis option sets or clears all display flags.
+[no]answerThis option displays [or does not display] the answer section of a reply. The default is to display it.
+[no]authorityThis option displays [or does not display] the authority section of a reply. The default is to display it.
+[no]besteffortThis option attempts to display [or does not display] the contents of messages which are malformed. The default is to not display malformed answers.
+burstThis option delays queries until the start of the next second.
+[no]clThis option displays [or does not display] the CLASS when printing the record.
+[no]commentsThis option toggles the display of comment lines in the output. The default is to print comments.
+[no]continueThis option toggles continuation on errors (e.g. timeouts).
+[no]cryptoThis 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]multilineThis 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
mdigoutput.+[no]questionThis 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]rrcommentsThis 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]shortThis option provides [or does not provide] a terse answer. The default is to print the answer in a verbose form.
+split=WThis option splits long hex- or base64-formatted fields in resource records into chunks of
Wcharacters (whereWis rounded up to the nearest multiple of 4).+nosplitor+split=0causes fields not to be split. The default is 56 characters, or 44 characters when multiline mode is active.+[no]tcpThis option uses [or does not use] TCP when querying name servers. The default behavior is to use UDP.
+[no]ttlidThis option displays [or does not display] the TTL when printing the record.
+[no]ttlunitsThis 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]vcThis option uses [or does not use] TCP when querying name servers. This alternate syntax to
+[no]tcpis provided for backwards compatibility. Thevcstands for “virtual circuit”.
Local Options¶
-c classThis 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 typeThis 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-xoption is supplied to indicate a reverse lookup with the “PTR” query type.-x addrReverse lookups - mapping addresses to names - are simplified by this option.
addris an IPv4 address in dotted-decimal notation, or a colon-delimited IPv6 address.mdigautomatically performs a lookup for a query name like11.12.13.10.in-addr.arpaand 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]aaflagThis is a synonym for
+[no]aaonly.+[no]aaonlyThis sets the
aaflag in the query.+[no]adflagThis 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=BThis sets the UDP message buffer size advertised using EDNS0 to
Bbytes. 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]cdflagThis 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]dnssecThis 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.
+noednsclears 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
codeand an optional payload ofvalueas a hexadecimal string.+noednsoptclears the EDNS options to be sent.+[no]expireThis toggles sending of an EDNS Expire option.
+[no]nsidThis toggles inclusion of an EDNS name server ID request when sending a query.
+[no]recurseThis toggles the setting of the RD (recursion desired) bit in the query. This bit is set by default, which means
mdignormally sends recursive queries.+retry=TThis sets the number of times to retry UDP queries to server to
Tinstead 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 simplymdig +subnet=0This 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=TThis sets the timeout for a query to
Tseconds. The default timeout is 5 seconds for UDP transport and 10 for TCP. An attempt to setTto less than 1 results in a query timeout of 1 second being applied.+tries=TThis sets the number of times to try UDP queries to server to
Tinstead of the default, 3. IfTis less than or equal to zero, the number of tries is silently rounded up to 1.+udptimeout=TThis sets the timeout between UDP query retries to
T.+[no]unknownformatThis 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]yamlThis toggles printing of the responses in a detailed YAML format.
+[no]zflagThis 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¶
-hThis option prints the usage summary and exits.
-jWhen loading a zonefile, this option instructs
namedto read the journal if it exists.-lThis 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).
-cThis option specifies that only the “core” configuration should be checked. This suppresses the loading of plugin modules, and causes all parameters to
pluginstatements to be ignored.-iThis option ignores warnings on deprecated options.
-pThis option prints out the
named.confand included files in canonical form if no errors were detected. See also the-xoption.-t directoryThis option instructs
namedto chroot todirectory, so thatincludedirectives in the configuration file are processed as if run by a similarly chrootednamed.-vThis option prints the version of the
named-checkconfprogram and exits.-xWhen printing the configuration files in canonical form, this option obscures shared secrets by replacing them with strings of question marks (
?). This allows the contents ofnamed.confand related files to be shared - for example, when submitting bug reports - without compromising private data. This option cannot be used without-p.-zThis option performs a test load of all zones of type
primaryfound innamed.conf.filenameThis 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.
See Also¶
named(8), named-checkzone(8), BIND 9 Administrator Reference Manual.
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¶
-dThis option enables debugging.
-hThis option prints the usage summary and exits.
-qThis option sets quiet mode, which only sets an exit code to indicate successful or failed completion.
-vThis option prints the version of the
named-checkzoneprogram and exits.-jWhen loading a zone file, this option tells
namedto read the journal if it exists. The journal file name is assumed to be the zone file name with the string.jnlappended.-J filenameWhen loading the zone file, this option tells
namedto read the journal from the given file, if it exists. This implies-j.-c classThis option specifies the class of the zone. If not specified,
INis assumed.-i modeThis option performs post-load zone integrity checks. Possible modes are
full(the default),full-sibling,local,local-sibling, andnone.Mode
fullchecks that MX records refer to A or AAAA records (both in-zone and out-of-zone hostnames). Modelocalonly checks MX records which refer to in-zone hostnames.Mode
fullchecks that SRV records refer to A or AAAA records (both in-zone and out-of-zone hostnames). Modelocalonly checks SRV records which refer to in-zone hostnames.Mode
fullchecks 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. Modelocalonly 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-siblingandlocal-siblingdisable sibling glue checks, but are otherwise the same asfullandlocal, respectively.Mode
nonedisables the checks.-f formatThis option specifies the format of the zone file. Possible formats are
text(the default),raw, andmap.-F formatThis 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, andmap,raw, andraw=N, which store the zone in a binary format for rapid loading bynamed.raw=Nspecifies the format version of the raw zone file: ifNis 0, the raw file can be read by any version ofnamed; if N is 1, the file can only be read by release 9.9.0 or higher. The default is 1.-k modeThis option performs
check-nameschecks with the specified failure mode. Possible modes arefail(the default fornamed-compilezone),warn(the default fornamed-checkzone), andignore.-l ttlThis 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-ttloption innamed.conf.-L serialWhen compiling a zone to
rawormapformat, 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 modeThis option specifies whether MX records should be checked to see if they are addresses. Possible modes are
fail,warn(the default), andignore.-M modeThis option checks whether a MX record refers to a CNAME. Possible modes are
fail,warn(the default), andignore.-n modeThis option specifies whether NS records should be checked to see if they are addresses. Possible modes are
fail(the default fornamed-compilezone),warn(the default fornamed-checkzone), andignore.-o filenameThis option writes the zone output to
filename. Iffilenameis-, then the zone output is written to standard output. This is mandatory fornamed-compilezone.-r modeThis 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), andignore.-s styleThis option specifies the style of the dumped zone file. Possible styles are
full(the default) andrelative. Thefullformat 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. Fornamed-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 modeThis option checks whether an SRV record refers to a CNAME. Possible modes are
fail,warn(the default), andignore.-t directoryThis option tells
namedto chroot todirectory, so thatincludedirectives in the configuration file are processed as if run by a similarly chrootednamed.-T modeThis 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) andignore.-w directoryThis option instructs
namedto chdir todirectory, so that relative filenames in master file$INCLUDEdirectives work. This is similar to the directory clause innamed.conf.-DThis option dumps the zone file in canonical format. This is always enabled for
named-compilezone.-W modeThis 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) andignore.zonenameThis indicates the domain name of the zone being checked.
filenameThis 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.
See Also¶
named(8), nsupdate(1), BIND 9 Administrator Reference Manual.
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¶
filenameThis is the name of the
.nzdfile whose contents should be printed.
See Also¶
BIND 9 Administrator Reference Manual.
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¶
-hThis option prints out the help menu.
-o originThis option specifies the origin to be used when interpreting the record.
-pThis option prints out the resulting record in canonical form. If there is no canonical form defined, the record is printed in unknown record format.
-uThis option prints out the resulting record in unknown record form.
-C,-T, and-PThese 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 };
HTTP¶
http string {
endpoints { quoted_string; ... };
};
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 ] { ( primaries | ipv4_address
[ port integer ] | ipv6_address [ port
integer ] ) [ key string ] [ tls
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 ] { ( primaries |
ipv4_address [ port integer ] | ipv6_address [ port
integer ] ) [ key string ] [ tls 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;
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 ] { ( primaries | ipv4_address [ port
integer ] | ipv6_address [ port integer ] ) [ key
string ] [ tls 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;// deprecated
heartbeat-interval integer;
hostname ( quoted_string | none );
http-port integer;
https-port integer;
interface-interval duration;
ipv4only-contact string;
ipv4only-enable boolean;
ipv4only-server string;
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 ] [ tls string ] [ http
string ] {
address_match_element; ... };
listen-on-v6 [ port integer ] [ dscp
integer ] [ tls string ] [ http
string ] {
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;
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 ] [ nsdname-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;
tls-port integer;
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 );
};
PLUGIN¶
plugin ( query ) string [ { unspecified-text
} ];
PRIMARIES¶
primaries string [ port integer ] [ dscp
integer ] { ( primaries | ipv4_address
[ port integer ] | ipv6_address [ port
integer ] ) [ key string ] [ tls
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; ...
} ];
};
TLS¶
tls string {
ca-file quoted_string;
cert-file quoted_string;
ciphers string; // experimental
dh-param quoted_string; // experimental
hostname quoted_string;
key-file quoted_string;
protocols sslprotos; // experimental
};
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 ] { ( primaries |
ipv4_address [ port integer ] | ipv6_address [ port
integer ] ) [ key string ] [ tls 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;
auto-dnssec ( allow | maintain | off );
cache-file quoted_string;
catalog-zones { zone string [ default-masters [ port integer ]
[ dscp integer ] { ( primaries | ipv4_address [ port
integer ] | ipv6_address [ port integer ] ) [ key
string ] [ tls 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;// deprecated
ipv4only-contact string;
ipv4only-enable boolean;
ipv4only-server string;
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;
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 ] [ nsdname-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 ] { (
primaries | ipv4_address [ port integer ] |
ipv6_address [ port integer ] ) [ key string ] [
tls 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 ] { (
primaries | ipv4_address [ port integer ] |
ipv6_address [ port integer ] ) [ key string ] [
tls 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;
primaries [ port integer ] [ dscp integer ] { (
primaries | ipv4_address [ port integer ] |
ipv6_address [ port integer ] ) [ key string ] [
tls 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 ] { ( primaries |
ipv4_address [ port integer ] | ipv6_address [ port
integer ] ) [ key string ] [ tls 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 ] { ( primaries |
ipv4_address [ port integer ] | ipv6_address [ port
integer ] ) [ key string ] [ tls 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;
primaries [ port integer ] [ dscp integer ] { ( primaries |
ipv4_address [ port integer ] | ipv6_address [ port
integer ] ) [ key string ] [ tls 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
See Also¶
named(8), named-checkconf(8), rndc(8), rndc-confgen(8), tsig-keygen(8), BIND 9 Administrator Reference Manual.
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¶
-4This option tells
namedto use only IPv4, even if the host machine is capable of IPv6.-4and-6are mutually exclusive.-6This option tells
namedto use only IPv6, even if the host machine is capable of IPv4.-4and-6are mutually exclusive.-c config-fileThis option tells
namedto useconfig-fileas 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 possibledirectoryoption in the configuration file,config-fileshould be an absolute pathname.-d debug-levelThis option sets the daemon’s debug level to
debug-level. Debugging traces fromnamedbecome more verbose as the debug level increases.-D stringThis option specifies a string that is used to identify a instance of
namedin a process listing. The contents ofstringare not examined.-E engine-nameWhen 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.-fThis option runs the server in the foreground (i.e., do not daemonize).
-gThis option runs the server in the foreground and forces all logging to
stderr.-L logfileThis option sets the log to the file
logfileby default, instead of the system log.-M optionThis 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 tofill, blocks of memory are filled with tag values when allocated or freed, to assist debugging of memory problems.nofilldisables this behavior, and is the default unlessnamedhas been compiled with developer options.-m flagThis option turns on memory usage debugging flags. Possible flags are
usage,trace,record,size, andmctx. These correspond to theISC_MEM_DEBUGXXXXflags described in<isc/mem.h>.-n #cpusThis option creates
#cpusworker threads to take advantage of multiple CPUs. If not specified,namedtries 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 valueThis option specifies the port(s) on which the server will listen for queries. If
valueis of the form<portnum>ordns=<portnum>, the server will listen for DNS queries onportnum; if not not specified, the default is port 53. Ifvalueis of the formtls=<portnum>, the server will listen for TLS queries onportnum; the default is 853. Ifvalueis of the formhttps=<portnum>, the server will listen for HTTPS queries onportnum; the default is 443. Ifvalueis of the formhttp=<portnum>, the server will listen for HTTP queries onportnum; the default is 80.-sThis option writes memory usage statistics to
stdouton exit.
Note
This option is mainly of interest to BIND 9 developers and may be removed or changed in a future release.
-S #max-socksThis option allows
namedto use up to#max-sockssockets. The default value is 21000 on systems built with default configuration options, and 4096 on systems built withconfigure --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 directoryThis option tells
namedto chroot todirectoryafter 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 #listenersThis option tells
namedthe number of#listenersworker threads to listen on, for incoming UDP packets on each address. If not specified,namedcalculates 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-nhas been set to a higher value than the number of detected CPUs, then-Umay 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 userThis option sets the setuid to
userafter 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.
-vThis option reports the version number and exits.
-VThis option reports the version number and build options, and exits.
-X lock-fileThis option acquires a lock on the specified file at runtime; this helps to prevent duplicate
namedinstances from running simultaneously. Use of this option overrides thelock-fileoption innamed.conf. If set tonone, the lock file check is disabled.-x cache-fileThis option loads data from
cache-fileinto 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.confThe default configuration file.
/var/run/named/named.pidThe 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¶
saltThis is the salt provided to the hash algorithm.
algorithmThis 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.
flagsThis is provided for compatibility with NSEC3 record presentation format, but is ignored since the flags do not affect the hash.
iterationsThis is the number of additional times the hash should be performed.
domainThis 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
hostusing the current default server or usingserver, if specified. Ifhostis an Internet address and the query type is A or PTR, the name of the host is returned. Ifhostis 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 domainThese commands change the default server to
domain;lserveruses the initial server to look up information aboutdomain, whileserveruses the current default server. If an authoritative answer cannot be found, the names of servers that might have the answer are returned.rootThis command is not implemented.
fingerThis command is not implemented.
lsThis command is not implemented.
viewThis command is not implemented.
helpThis command is not implemented.
?This command is not implemented.
exitThis command exits the program.
set keyword[=value]This command is used to change state information that affects the lookups. Valid keywords are:
allThis keyword prints the current values of the frequently used options to
set. Information about the current default server and host is also printed.class=valueThis keyword changes the query class to one of:
INthe Internet class
CHthe Chaos class
HSthe Hesiod class
ANYwildcard
The class specifies the protocol group of the information. The default is
IN; the abbreviation for this keyword iscl.nodebugThis 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.nod2This keyword turns debugging mode on or off. This displays more about what nslookup is doing. The default is
nod2.domain=nameThis keyword sets the search list to
name.nosearchIf 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=valueThis keyword changes the default TCP/UDP name server port to
valuefrom its default, port 53. The abbreviation for this keyword ispo.querytype=value|type=valueThis keyword changes the type of the information query to
value. The defaults are A and then AAAA; the abbreviations for these keywords areqandty.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.
norecurseThis 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=numberThis keyword sets the number of dots (label separators) in a domain that disables searching. Absolute names always stop searching.
retry=numberThis keyword sets the number of retries to
number.timeout=numberThis keyword changes the initial timeout interval to wait for a reply to
number, in seconds.novcThis keyword indicates that a virtual circuit should always be used when sending requests to the server.
novcis the default.nofailThis 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
See Also¶
dig(1), host(1), named(8).
nsupdate - dynamic DNS update utility¶
Synopsis¶
nsupdate [-d] [-D] [-i] [-L level] [ [-g] | [-o] | [-l] | [-y [hmac:]keyname:secret] | [-k keyfile] ] [-t timeout] [-u udptimeout] [-r udpretries] [-v] [-T] [-P] [-V] [ [-4] | [-6] ] [filename]
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¶
-4This option sets use of IPv4 only.
-6This option sets use of IPv6 only.
-dThis option sets debug mode, which provides tracing information about the update requests that are made and the replies received from the name server.
-DThis option sets extra debug mode.
-iThis option forces interactive mode, even when standard input is not a terminal.
-k keyfileThis option indicates the file containing the TSIG authentication key. Keyfiles may be in two formats: a single file containing a
named.conf-formatkeystatement, which may be generated automatically byddns-confgen; or a pair of files whose names are of the formatK{name}.+157.+{random}.keyandK{name}.+157.+{random}.private, which can be generated bydnssec-keygen. The-koption 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.-lThis option sets local-host only mode, which sets the server address to localhost (disabling the
serverso 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 bynamedif any localprimaryzone has setupdate-policytolocal. The location of this key file can be overridden with the-koption.-L levelThis option sets the logging debug level. If zero, logging is disabled.
-p portThis option sets the port to use for connections to a name server. The default is 53.
-PThis option prints the list of private BIND-specific resource record types whose format is understood by
nsupdate. See also the-Toption.-r udpretriesThis option sets the number of UDP retries. The default is 3. If zero, only one update request is made.
-t timeoutThis 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.
-TThis option prints the list of IANA standard resource record types whose format is understood by
nsupdate.nsupdateexits after the lists are printed. The-Toption can be combined with the-Poption.Other types can be entered using
TYPEXXXXXwhereXXXXXis 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 udptimeoutThis 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.
-vThis option specifies that TCP should be used even for small update requests. By default,
nsupdateuses 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.-VThis option prints the version number and exits.
-y [hmac:]keyname:secretThis option sets the literal TSIG authentication key.
keynameis the name of the key, andsecretis the base64 encoded shared secret.hmacis the name of the key algorithm; valid choices arehmac-md5,hmac-sha1,hmac-sha224,hmac-sha256,hmac-sha384, orhmac-sha512. Ifhmacis not specified, the default ishmac-md5, or if MD5 was disabled,hmac-sha256.NOTE: Use of the
-yoption 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 portThis command sends all dynamic update requests to the name server
servername. When no server statement is provided,nsupdatesends 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.portis the port number onservernamewhere the dynamic update requests are sent. If no port number is specified, the default DNS port number of 53 is used.local address portThis command sends all dynamic update requests using the local
address. When no local statement is provided,nsupdatesends updates using an address and port chosen by the system.portcan also be used to force requests to come from a specific port. If no port number is specified, the system assigns one.zone zonenameThis command specifies that all updates are to be made to the zone
zonename. If nozonestatement is provided,nsupdateattempts to determine the correct zone to update based on the rest of the input.class classnameThis command specifies the default class. If no
classis specified, the default class isIN.ttl secondsThis command specifies the default time-to-live, in seconds, for records to be added. The value
noneclears the default TTL.key hmac:keyname secretThis command specifies that all updates are to be TSIG-signed using the
keyname-secretpair. Ifhmacis specified, it sets the signing algorithm in use. The default ishmac-md5; if MD5 was disabled, the default ishmac-sha256. Thekeycommand overrides any key specified on the command line via-yor-k.gsstsigThis command uses GSS-TSIG to sign the updates. This is equivalent to specifying
-gon the command line.oldgsstsigThis command uses the Windows 2000 version of GSS-TSIG to sign the updates. This is equivalent to specifying
-oon the command line.realm [realm_name]When using GSS-TSIG, this command specifies the use of
realm_namerather than the default realm inkrb5.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-nameThis command requires that no resource record of any type exist with the name
domain-name.prereq yxdomain domain-nameThis command requires that
domain-nameexist (as at least one resource record, of any type).prereq nxrrset domain-name class typeThis command requires that no resource record exist of the specified
type,class, anddomain-name. Ifclassis omitted, IN (Internet) is assumed.prereq yxrrset domain-name class typeThis command requires that a resource record of the specified
type,classanddomain-nameexist. Ifclassis omitted, IN (internet) is assumed.prereq yxrrset domain-name class type dataWith this command, the
datafrom each set of prerequisites of this form sharing a commontype,class, anddomain-nameare combined to form a set of RRs. This set of RRs must exactly match the set of RRs existing in the zone at the giventype,class, anddomain-name. Thedataare written in the standard text representation of the resource record’s RDATA.update delete domain-name ttl class type dataThis command deletes any resource records named
domain-name. Iftypeanddataare provided, only matching resource records are removed. The Internet class is assumed ifclassis not supplied. Thettlis ignored, and is only allowed for compatibility.update add domain-name ttl class type dataThis command adds a new resource record with the specified
ttl,class, anddata.showThis command displays the current message, containing all of the prerequisites and updates specified since the last send.
sendThis command sends the current message. This is equivalent to entering a blank line.
answerThis command displays the answer.
debugThis command turns on debugging.
versionThis command prints the version number.
helpThis 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.confUsed to identify the default name server
/var/run/named/session.keySets the default TSIG key for use in local-only mode
K{name}.+157.+{random}.keyBase-64 encoding of the HMAC-MD5 key created by
dnssec-keygen.K{name}.+157.+{random}.privateBase-64 encoding of the HMAC-MD5 key created by
dnssec-keygen.
See Also¶
RFC 2136, RFC 3007, RFC 2104, RFC 2845, RFC 1034, RFC 2535, RFC 2931, named(8), dnssec-keygen(8), tsig-keygen(8).
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 moduleThis 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 slotThis option opens the session with the given PKCS#11 slot. The default is slot 0.
-i IDThis option destroys keys with the given object ID.
-l labelThis option destroys keys with the given label.
-p PINThis option specifies the
PINfor the device. If noPINis provided on the command line,pkcs11-destroyprompts for it.-w secondsThis 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.
See Also¶
pkcs11-keygen(8), pkcs11-list(8), pkcs11-tokens(8)
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 algorithmThis option specifies the key algorithm class: supported classes are RSA, DSA, DH, ECC, and ECX. In addition to these strings, the
algorithmcan 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 isRSA.-b keysizeThis option creates the key pair with
keysizebits 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.-eFor RSA keys only, this option specifies use of a large exponent.
-i idThis option creates key objects with
id. The ID is either an unsigned short 2-byte or an unsigned long 4-byte number.-m moduleThis 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.
-PThis 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 PINThis option specifies the
PINfor the device. If noPINis provided on the command line,pkcs11-keygenprompts for it.-qThis option sets quiet mode, which suppresses unnecessary output.
-SFor 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 slotThis option opens the session with the given PKCS#11 slot. The default is slot 0.
See Also¶
pkcs11-destroy(8), pkcs11-list(8), pkcs11-tokens(8), dnssec-keyfromlabel(8)
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¶
-PThis option lists only the public objects. (Note that on some PKCS#11 devices, all objects are private.)
-m moduleThis 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 slotThis option opens the session with the given PKCS#11 slot. The default is slot 0.
-i IDThis option lists only key objects with the given object ID.
-l labelThis option lists only key objects with the given label.
-p PINThis option specifies the
PINfor the device. If noPINis provided on the command line,pkcs11-listprompts for it.
See Also¶
pkcs11-destroy(8), pkcs11-keygen(8), pkcs11-tokens(8)
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 moduleThis 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.
-vThis option makes the PKCS#11 libisc initialization verbose.
See Also¶
pkcs11-destroy(8), pkcs11-keygen(8), pkcs11-list(8)
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¶
-aThis option sets automatic
rndcconfiguration, which creates a filerndc.keyin/etc(or a differentsysconfdirspecified when BIND was built) that is read by bothrndcandnamedon startup. Therndc.keyfile defines a default command channel and authentication key allowingrndcto communicate withnamedon the local host with no further configuration.If a more elaborate configuration than that generated by
rndc-confgen -ais required, for example if rndc is to be used remotely, runrndc-confgenwithout the-aoption and set uprndc.confandnamed.confas directed.-A algorithmThis 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 keysizeThis 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 keyfileThis option is used with the
-aoption to specify an alternate location forrndc.key.-hThis option prints a short summary of the options and arguments to
rndc-confgen.-k keynameThis option specifies the key name of the
rndcauthentication key. This must be a valid domain name. The default isrndc-key.-p portThis option specifies the command channel port where
namedlistens for connections fromrndc. The default is 953.-qThis option prevets printing the written path in automatic configuration mode.
-s addressThis option specifies the IP address where
namedlistens for command-channel connections fromrndc. The default is the loopback address 127.0.0.1.-t chrootdirThis option is used with the
-aoption to specify a directory wherenamedruns chrooted. An additional copy of therndc.keyis written relative to this directory, so that it is found by the chrootednamed.-u userThis option is used with the
-aoption to set the owner of the generatedrndc.keyfile. If-tis 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
See Also¶
rndc(8), rndc.conf(5), named(8), BIND 9 Administrator Reference Manual.
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.
See Also¶
rndc(8), rndc-confgen(8), mmencode(1), BIND 9 Administrator Reference Manual.
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¶
-4This option indicates use of IPv4 only.
-6This option indicates use of IPv6 only.
-b source-addressThis option indicates
source-addressas 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-fileThis option indicates
config-fileas the configuration file instead of the default,/etc/rndc.conf.-k key-fileThis option indicates
key-fileas the key file instead of the default,/etc/rndc.key. The key in/etc/rndc.keyis used to authenticate commands sent to the server if the config-file does not exist.-s serverserveris the name or address of the server which matches a server statement in the configuration file forrndc. If no server is supplied on the command line, the host named by the default-server clause in the options statement of therndcconfiguration file is used.-p portThis option instructs BIND 9 to send commands to TCP port
portinstead of its default control channel port, 953.-qThis option sets quiet mode, where message text returned by the server is not printed unless there is an error.
-rThis option instructs
rndcto print the result code returned bynamedafter executing the requested command (e.g., ISC_R_SUCCESS, ISC_R_FAILURE, etc.).-VThis option enables verbose logging.
-y key_idThis option indicates use of the key
key_idfrom the configuration file. For control message validation to succeed,key_idmust be known bynamedwith the same algorithm and secret string. If nokey_idis specified,rndcfirst 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:
addzonezone [class [view]] configurationThis command adds a zone while the server is running. This command requires the
allow-new-zonesoption to be set toyes. The configuration string specified on the command line is the zone configuration text that would ordinarily be placed innamed.conf.The configuration is saved in a file called
viewname.nzf(or, ifnamedis compiled with liblmdb, an LMDB database file calledviewname.nzd).viewnameis 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. Whennamedis restarted, the file is loaded into the view configuration so that zones that were added can persist after a restart.This sample
addzonecommand adds the zoneexample.comto 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 delzoneandrndc modzone.delzone[-clean] zone [class [view]]This command deletes a zone while the server is running.
If the
-cleanargument is specified, the zone’s master file (and journal file, if any) are deleted along with the zone. Without the-cleanoption, zone files must be deleted manually. (If the zone is of typesecondaryorstub, the files needing to be removed are reported in the output of therndc delzonecommand.)If the zone was originally added via
rndc addzone, then it is removed permanently. However, if it was originally configured innamed.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 fromnamed.conf.See also
rndc addzoneandrndc 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 -statusshow the DNSSEC signing state for the specified zone.rndc dnssec -rolloverallows you to schedule key rollover for a specific key (overriding the original key lifetime).rndc dnssec -checkdswill letnamedknow 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 idargument 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 algorithmto 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 -reopenallows the output file to be renamed externally, so thatnamedcan truncate and re-open it.rndc dnstap -rollcauses 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. Ifnumberis specified, then the number of backup log files is limited to that number.dumpdb[-all | -cache | -zones | -adb | -bad | -expired | -fail] [view …]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-fileoption in the BIND 9 Administrator Reference Manual.)flushThis command flushes the server’s cache.
flushnamename [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.
flushtreename [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.
See also
rndc thaw.halt[-p]This command stops the server immediately. Recent changes made through dynamic update or IXFR are not saved to the master files, but are rolled forward from the journal files when the server is restarted. If
-pis specified,named’s process ID is returned. This allows an external process to determine whennamedhas completed halting.See also
rndc stop.loadkeys[zone [class [view]]]This command fetches all DNSSEC keys for the given zone from the key directory. If they are within their publication period, they are merged into the zone’s DNSKEY RRset. Unlike
rndc sign, however, the zone is not immediately re-signed by the new keys, but is allowed to incrementally re-sign over time.This command requires that the zone be configured with a
dnssec-policy, or that theauto-dnsseczone option be set tomaintain, and also requires the zone to be configured to allow dynamic DNS. (See “Dynamic Update Policies” in the Administrator Reference Manual for more details.)managed-keys(status | refresh | sync | destroy) [class [view]]This command inspects and controls the “managed-keys” database which handles RFC 5011 DNSSEC trust anchor maintenance. If a view is specified, these commands are applied to that view; otherwise, they are applied to all views.
When run with the
statuskeyword, this prints the current status of the managed-keys database.When run with the
refreshkeyword, this forces an immediate refresh query to be sent for all the managed keys, updating the managed-keys database if any new keys are found, without waiting the normal refresh interval.When run with the
synckeyword, this forces an immediate dump of the managed-keys database to disk (in the filemanaged-keys.bindor (viewname.mkeys). This synchronizes the database with its journal file, so that the database’s current contents can be inspected visually.When run with the
destroykeyword, the managed-keys database is shut down and deleted, and all key maintenance is terminated. This command should be used only with extreme caution.Existing keys that are already trusted are not deleted from memory; DNSSEC validation can continue after this command is used. However, key maintenance operations cease until
namedis restarted or reconfigured, and all existing key maintenance states are deleted.Running
rndc reconfigor restartingnamedimmediately after this command causes key maintenance to be reinitialized from scratch, just as if the server were being started for the first time. This is primarily intended for testing, but it may also be used, for example, to jumpstart the acquisition of new keys in the event of a trust anchor rollover, or as a brute-force repair for key maintenance problems.
modzonezone [class [view]] configurationThis command modifies the configuration of a zone while the server is running. This command requires the
allow-new-zonesoption to be set toyes. As withaddzone, the configuration string specified on the command line is the zone configuration text that would ordinarily be placed innamed.conf.If the zone was originally added via
rndc addzone, the configuration changes are recorded permanently and are still in effect after the server is restarted or reconfigured. However, if it was originally configured innamed.conf, then that original configuration remains in place; when the server is restarted or reconfigured, the zone reverts to its original configuration. To make the changes permanent, it must also be modified innamed.conf.See also
rndc addzoneandrndc delzone.notifyzone [class [view]]This command resends NOTIFY messages for the zone.
notraceThis command sets the server’s debugging level to 0.
See also
rndc trace.nta[( -class class | -dump | -force | -remove | -lifetime duration)] domain [view]This command sets a DNSSEC negative trust anchor (NTA) for
domain, with a lifetime ofduration. The default lifetime is configured innamed.confvia thenta-lifetimeoption, and defaults to one hour. The lifetime cannot exceed one week.A negative trust anchor selectively disables DNSSEC validation for zones that are known to be failing because of misconfiguration rather than an attack. When data to be validated is at or below an active NTA (and above any other configured trust anchors),
namedaborts the DNSSEC validation process and treats the data as insecure rather than bogus. This continues until the NTA’s lifetime has elapsed.NTAs persist across restarts of the
namedserver. The NTAs for a view are saved in a file calledname.nta, wherenameis the name of the view; if it contains characters that are incompatible with use as a file name, a cryptographic hash is generated from the name of the view.An existing NTA can be removed by using the
-removeoption.An NTA’s lifetime can be specified with the
-lifetimeoption. TTL-style suffixes can be used to specify the lifetime in seconds, minutes, or hours. If the specified NTA already exists, its lifetime is updated to the new value. Settinglifetimeto zero is equivalent to-remove.If
-dumpis used, any other arguments are ignored and a list of existing NTAs is printed. Note that this may include NTAs that are expired but have not yet been cleaned up.Normally,
namedperiodically tests to see whether data below an NTA can now be validated (see thenta-recheckoption in the Administrator Reference Manual for details). If data can be validated, then the NTA is regarded as no longer necessary and is allowed to expire early. The-forceparameter overrides this behavior and forces an NTA to persist for its entire lifetime, regardless of whether data could be validated if the NTA were not present.The view class can be specified with
-class. The default is classIN, which is the only class for which DNSSEC is currently supported.All of these options can be shortened, i.e., to
-l,-r,-d,-f, and-c.Unrecognized options are treated as errors. To refer to a domain or view name that begins with a hyphen, use a double-hyphen (–) on the command line to indicate the end of options.
querylog[(on | off)]This command enables or disables query logging. For backward compatibility, this command can also be used without an argument to toggle query logging on and off.
Query logging can also be enabled by explicitly directing the
queriescategoryto achannelin theloggingsection ofnamed.conf, or by specifyingquerylog yes;in theoptionssection ofnamed.conf.reconfigThis command reloads the configuration file and loads new zones, but does not reload existing zone files even if they have changed. This is faster than a full
reloadwhen there is a large number of zones, because it avoids the need to examine the modification times of the zone files.recursingThis command dumps the list of queries
namedis currently recursing on, and the list of domains to which iterative queries are currently being sent. The second list includes the number of fetches currently active for the given domain, and how many have been passed or dropped because of thefetches-per-zoneoption.refreshzone [class [view]]This command schedules zone maintenance for the given zone.
reloadThis command reloads the configuration file and zones.
reloadzone [class [view]]This command reloads the given zone.
retransferzone [class [view]]This command retransfers the given secondary zone from the primary server.
If the zone is configured to use
inline-signing, the signed version of the zone is discarded; after the retransfer of the unsigned version is complete, the signed version is regenerated with new signatures.scanThis command scans the list of available network interfaces for changes, without performing a full
reconfigor waiting for theinterface-intervaltimer.secroots[-] [view …]This command dumps the security roots (i.e., trust anchors configured via
trust-anchors, or themanaged-keysortrusted-keysstatements [both deprecated], ordnssec-validation auto) and negative trust anchors for the specified views. If no view is specified, all views are dumped. Security roots indicate whether they are configured as trusted keys, managed keys, or initializing managed keys (managed keys that have not yet been updated by a successful key refresh query).If the first argument is
-, then the output is returned via therndcresponse channel and printed to the standard output. Otherwise, it is written to the secroots dump file, which defaults tonamed.secroots, but can be overridden via thesecroots-fileoption innamed.conf.See also
rndc managed-keys.serve-stale(on | off | reset | status) [class [view]]This command enables, disables, resets, or reports the current status of the serving of stale answers as configured in
named.conf.If serving of stale answers is disabled by
rndc-serve-stale off, then it remains disabled even ifnamedis reloaded or reconfigured.rndc serve-stale resetrestores the setting as configured innamed.conf.rndc serve-stale statusreports whether serving of stale answers is currently enabled, disabled by the configuration, or disabled byrndc. It also reports the values ofstale-answer-ttlandmax-stale-ttl.showzonezone [class [view]]This command prints the configuration of a running zone.
See also
rndc zonestatus.signzone [class [view]]This command fetches all DNSSEC keys for the given zone from the key directory (see the
key-directoryoption in the BIND 9 Administrator Reference Manual). If they are within their publication period, they are merged into the zone’s DNSKEY RRset. If the DNSKEY RRset is changed, then the zone is automatically re-signed with the new key set.This command requires that the zone be configured with a
dnssec-policy, or that theauto-dnsseczone option be set toallowormaintain, and also requires the zone to be configured to allow dynamic DNS. (See “Dynamic Update Policies” in the BIND 9 Administrator Reference Manual for more details.)See also
rndc loadkeys.signing[(-list | -clear keyid/algorithm | -clear all | -nsec3param ( parameters | none ) | -serial value ) zone [class [view]]This command lists, edits, or removes the DNSSEC signing-state records for the specified zone. The status of ongoing DNSSEC operations, such as signing or generating NSEC3 chains, is stored in the zone in the form of DNS resource records of type
sig-signing-type.rndc signing -listconverts these records into a human-readable form, indicating which keys are currently signing or have finished signing the zone, and which NSEC3 chains are being created or removed.rndc signing -clearcan remove a single key (specified in the same format thatrndc signing -listuses to display it), or all keys. In either case, only completed keys are removed; any record indicating that a key has not yet finished signing the zone is retained.rndc signing -nsec3paramsets the NSEC3 parameters for a zone. This is the only supported mechanism for using NSEC3 withinline-signingzones. Parameters are specified in the same format as an NSEC3PARAM resource record:hash algorithm,flags,iterations, andsalt, in that order.Currently, the only defined value for
hash algorithmis1, representing SHA-1. Theflagsmay be set to0or1, depending on whether the opt-out bit in the NSEC3 chain should be set.iterationsdefines the number of additional times to apply the algorithm when generating an NSEC3 hash. Thesaltis a string of data expressed in hexadecimal, a hyphen (-‘) if no salt is to be used, or the keyword ``auto`, which causesnamedto generate a random 64-bit salt.So, for example, to create an NSEC3 chain using the SHA-1 hash algorithm, no opt-out flag, 10 iterations, and a salt value of “FFFF”, use:
rndc signing -nsec3param 1 0 10 FFFF zone. To set the opt-out flag, 15 iterations, and no salt, use:rndc signing -nsec3param 1 1 15 - zone.rndc signing -nsec3param noneremoves an existing NSEC3 chain and replaces it with NSEC.rndc signing -serial valuesets the serial number of the zone tovalue. If the value would cause the serial number to go backwards, it is rejected. The primary use of this parameter is to set the serial number on inline signed zones.statsThis command writes server statistics to the statistics file. (See the
statistics-fileoption in the BIND 9 Administrator Reference Manual.)statusThis command displays the status of the server. Note that the number of zones includes the internal
bind/CHzone and the default./INhint zone, if there is no explicit root zone configured.stop-pThis command stops the server, making sure any recent changes made through dynamic update or IXFR are first saved to the master files of the updated zones. If
-pis specified,named(8)`'s process ID is returned. This allows an external process to determine when ``namedhas completed stopping.See also
rndc halt.sync-clean [zone [class [view]]]This command syncs changes in the journal file for a dynamic zone to the master file. If the “-clean” option is specified, the journal file is also removed. If no zone is specified, then all zones are synced.
tcp-timeouts[initial idle keepalive advertised]When called without arguments, this command displays the current values of the
tcp-initial-timeout,tcp-idle-timeout,tcp-keepalive-timeout, andtcp-advertised-timeoutoptions. When called with arguments, these values are updated. This allows an administrator to make rapid adjustments when under a denial-of-service (DoS) attack. See the descriptions of these options in the BIND 9 Administrator Reference Manual for details of their use.thaw[zone [class [view]]]This command enables updates to a frozen dynamic zone. If no zone is specified, then all frozen zones are enabled. This causes the server to reload the zone from disk, and re-enables dynamic updates after the load has completed. After a zone is thawed, dynamic updates are no longer refused. If the zone has changed and the
ixfr-from-differencesoption is in use, the journal file is updated to reflect changes in the zone. Otherwise, if the zone has changed, any existing journal file is removed.See also
rndc freeze.traceThis command increments the server’s debugging level by one.
tracelevelThis command sets the server’s debugging level to an explicit value.
See also
rndc notrace.tsig-deletekeyname [view]This command deletes a given TKEY-negotiated key from the server. This does not apply to statically configured TSIG keys.
tsig-listThis command lists the names of all TSIG keys currently configured for use by
namedin each view. The list includes both statically configured keys and dynamic TKEY-negotiated keys.validation(on | off | status) [view …]``This command enables, disables, or checks the current status of DNSSEC validation. By default, validation is enabled.
The cache is flushed when validation is turned on or off to avoid using data that might differ between states.
zonestatuszone [class [view]]This command displays the current status of the given zone, including the master file name and any include files from which it was loaded, when it was most recently loaded, the current serial number, the number of nodes, whether the zone supports dynamic updates, whether the zone is DNSSEC signed, whether it uses automatic DNSSEC key management or inline signing, and the scheduled refresh or expiry times for the zone.
See also
rndc showzone.
rndc commands that specify zone names, such as reload,
retransfer, or zonestatus, can be ambiguous when applied to zones
of type redirect. Redirect zones are always called ., and can be
confused with zones of type hint or with secondary copies of the root
zone. To specify a redirect zone, use the special zone name
-redirect, without a trailing period. (With a trailing period, this
would specify a zone called “-redirect”.)
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.
See Also¶
rndc.conf(5), rndc-confgen(8), named(8), named.conf(5), ndc(8), BIND 9 Administrator Reference Manual.
tsig-keygen, ddns-confgen - TSIG 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 key name can specified using -k
parameter and defaults to ddns-key. 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 algorithmThis 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.
-hThis option prints a short summary of options and arguments.
-k keynameThis option specifies the key name of the DDNS authentication key. The default is
ddns-keywhen neither the-snor-zoption is specified; otherwise, the default isddns-keyas 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-confgenonly)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-confgenonly)This option generates a configuration example to allow dynamic updates of a single hostname. The example
named.conftext shows how to set an update policy for the specified name using the “name” nametype. The default key name isddns-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-zoption.-z zone(ddns-confgenonly)This option generates a configuration example to allow dynamic updates of a zone. The example
named.conftext 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-soption.
See Also¶
nsupdate(1), named.conf(5), named(8), BIND 9 Administrator Reference Manual.