3853N/A - Copyright (C) 2004-2014 Internet Systems Consortium, Inc. ("ISC") 3853N/A - Copyright (C) 2000-2003 Internet Software Consortium. 3853N/A - Permission to use, copy, modify, and/or distribute this software for any 3853N/A - purpose with or without fee is hereby granted, provided that the above 3853N/A - copyright notice and this permission notice appear in all copies. 3853N/A - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 3853N/A - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 3853N/A - AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 3853N/A - INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 3853N/A - LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 3853N/A - OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 3853N/A - PERFORMANCE OF THIS SOFTWARE. 3853N/A<
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3853N/A<
tr><
th colspan="3" align="center"><
span class="application">nsupdate</
span></
th></
tr>
3853N/A<
td width="20%" align="left">
3853N/A<
th width="60%" align="center">Manual pages</
th>
3853N/A<
div class="refentry" lang="en">
3853N/A<
p><
span class="application">nsupdate</
span> — Dynamic DNS update utility</
p>
3853N/A<
div class="refsynopsisdiv">
3853N/A<
div class="cmdsynopsis"><
p><
code class="command">nsupdate</
code> [<
code class="option">-d</
code>] [<
code class="option">-D</
code>] [[<
code class="option">-g</
code>] | [<
code class="option">-o</
code>] | [<
code class="option">-l</
code>] | [<
code class="option">-y <
em class="replaceable"><
code>[<
span class="optional">hmac:</
span>]keyname:secret</
code></
em></
code>] | [<
code class="option">-k <
em class="replaceable"><
code>keyfile</
code></
em></
code>]] [<
code class="option">-t <
em class="replaceable"><
code>timeout</
code></
em></
code>] [<
code class="option">-u <
em class="replaceable"><
code>udptimeout</
code></
em></
code>] [<
code class="option">-r <
em class="replaceable"><
code>udpretries</
code></
em></
code>] [<
code class="option">-R <
em class="replaceable"><
code>randomdev</
code></
em></
code>] [<
code class="option">-v</
code>] [<
code class="option">-T</
code>] [<
code class="option">-P</
code>] [filename]</
p></
div>
3853N/A<
div class="refsect1" lang="en">
3853N/A<
a name="id2645932"></
a><
h2>DESCRIPTION</
h2>
3853N/A<
p><
span><
strong class="command">nsupdate</
strong></
span>
3853N/A is used to submit Dynamic DNS Update requests as defined in RFC 2136
3853N/A This allows resource records to be added or removed from a zone
3853N/A without manually editing the zone file.
3853N/A A single update request can contain requests to add or remove more than
3853N/A Zones that are under dynamic control via
3853N/A <
span><
strong class="command">nsupdate</
strong></
span>
3853N/A or a DHCP server should not be edited by hand.
3853N/A conflict with dynamic updates and cause data to be lost.
3853N/A The resource records that are dynamically added or removed with
3853N/A <
span><
strong class="command">nsupdate</
strong></
span>
3853N/A have to be in the same zone.
3853N/A Requests are sent to the zone's master server.
3853N/A This is identified by the MNAME field of the zone's SOA record.
3853N/A <
code class="option">-d</
code>
3853N/A <
span><
strong class="command">nsupdate</
strong></
span>
3853N/A This provides tracing information about the update requests that are
3853N/A made and the replies received from the name server.
3853N/A The <
code class="option">-D</
code> option makes <
span><
strong class="command">nsupdate</
strong></
span>
3853N/A report additional debugging information to <
code class="option">-d</
code>.
3853N/A The <
code class="option">-L</
code> option with an integer argument of zero or
3853N/A higher sets the logging debug level. If zero, logging is disabled.
3853N/A Transaction signatures can be used to authenticate the Dynamic
3853N/A DNS updates. These use the TSIG resource record type described
3853N/A in RFC 2845 or the SIG(0) record described in RFC 2535 and
3853N/A RFC 2931 or GSS-TSIG as described in RFC 3645. TSIG relies on
3853N/A a shared secret that should only be known to
3853N/A <
span><
strong class="command">nsupdate</
strong></
span> and the name server. Currently,
3853N/A the only supported encryption algorithm for TSIG is HMAC-MD5,
3853N/A which is defined in RFC 2104. Once other algorithms are
3853N/A defined for TSIG, applications will need to ensure they select
3853N/A the appropriate algorithm as well as the key when authenticating
3853N/A each other. For instance, suitable <
span class="type">key</
span> and
3853N/A <
span class="type">server</
span> statements would be added to
3853N/A can associate the appropriate secret key and algorithm with
3853N/A the IP address of the client application that will be using
3853N/A TSIG authentication. SIG(0) uses public key cryptography.
3853N/A To use a SIG(0) key, the public key must be stored in a KEY
3853N/A record in a zone served by the name server.
3853N/A <
span><
strong class="command">nsupdate</
strong></
span> does not read
3853N/A GSS-TSIG uses Kerberos credentials. Standard GSS-TSIG mode
3853N/A is switched on with the <
code class="option">-g</
code> flag. A
3853N/A non-standards-compliant variant of GSS-TSIG used by Windows
3853N/A 2000 can be switched on with the <
code class="option">-o</
code> flag.
3853N/A<
p><
span><
strong class="command">nsupdate</
strong></
span>
3853N/A uses the <
code class="option">-y</
code> or <
code class="option">-k</
code> option
3853N/A to provide the shared secret needed to generate a TSIG record
3853N/A for authenticating Dynamic DNS update requests, default type
3853N/A HMAC-MD5. These options are mutually exclusive.
3853N/A When the <
code class="option">-y</
code> option is used, a signature is
3853N/A [<
span class="optional"><
em class="parameter"><
code>hmac:</
code></
em></
span>]<
em class="parameter"><
code>keyname:secret.</
code></
em>
3853N/A <
em class="parameter"><
code>keyname</
code></
em> is the name of the key, and
3853N/A <
em class="parameter"><
code>secret</
code></
em> is the base64 encoded shared secret.
3853N/A Use of the <
code class="option">-y</
code> option is discouraged because the
3853N/A shared secret is supplied as a command line argument in clear text.
3853N/A This may be visible in the output from
3853N/A <
span class="citerefentry"><
span class="refentrytitle">ps</
span>(1)</
span>
3853N/A or in a history file maintained by the user's shell.
3853N/A <
code class="option">-k</
code> option, <
span><
strong class="command">nsupdate</
strong></
span> reads
3853N/A the shared secret from the file <
em class="parameter"><
code>keyfile</
code></
em>.
3853N/A Keyfiles may be in two formats: a single file containing
3853N/A a <
code class="filename">
named.conf</
code>-format <
span><
strong class="command">key</
strong></
span>
3853N/A statement, which may be generated automatically by
3853N/A <
span><
strong class="command">ddns-confgen</
strong></
span>, or a pair of files whose names are
3853N/A of the format <
code class="filename">K{name}.+157.+{random}.key</
code> and
3853N/A <
code class="filename">K{name}.+157.+{random}.private</
code>, which can be
3853N/A generated by <
span><
strong class="command">dnssec-keygen</
strong></
span>.
3853N/A The <
code class="option">-k</
code> may also be used to specify a SIG(0) key used
3853N/A to authenticate Dynamic DNS update requests. In this case, the key
3853N/A specified is not an HMAC-MD5 key.
3853N/A <
span><
strong class="command">nsupdate</
strong></
span> can be run in a local-host only mode
3853N/A using the <
code class="option">-l</
code> flag. This sets the server address to
3853N/A localhost (disabling the <
span><
strong class="command">server</
strong></
span> so that the server
3853N/A address cannot be overridden). Connections to the local server will
3853N/A which is automatically generated by <
span><
strong class="command">named</
strong></
span> if any
3853N/A local master zone has set <
span><
strong class="command">update-policy</
strong></
span> to
3853N/A <
span><
strong class="command">local</
strong></
span>. The location of this key file can be
3853N/A overridden with the <
code class="option">-k</
code> option.
3853N/A By default, <
span><
strong class="command">nsupdate</
strong></
span>
3853N/A uses UDP to send update requests to the name server unless they are too
3853N/A large to fit in a UDP request in which case TCP will be used.
3853N/A <
code class="option">-v</
code>
3853N/A <
span><
strong class="command">nsupdate</
strong></
span>
3853N/A This may be preferable when a batch of update requests is made.
3853N/A The <
code class="option">-p</
code> sets the default port number to use for
3853N/A connections to a name server. The default is 53.
3853N/A The <
code class="option">-t</
code> option sets the maximum time an update request
3853N/A take before it is aborted. The default is 300 seconds. Zero can be
3853N/A The <
code class="option">-u</
code> option sets the UDP retry interval. The default
3853N/A 3 seconds. If zero, the interval will be computed from the timeout
3853N/A The <
code class="option">-r</
code> option sets the number of UDP retries. The
3853N/A 3. If zero, only one update request will be made.
3853N/A The <
code class="option">-R <
em class="replaceable"><
code>randomdev</
code></
em></
code> option
3853N/A specifies a source of randomness. If the operating system
3853N/A equivalent device, the default source of randomness is keyboard
3853N/A input. <
code class="filename">randomdev</
code> specifies the name of
3853N/A a character device or file containing random data to be used
3853N/A instead of the default. The special value
3853N/A <
code class="filename">keyboard</
code> indicates that keyboard input
3853N/A should be used. This option may be specified multiple times.
3853N/A Other types can be entered using "TYPEXXXXX" where "XXXXX" is the
3853N/A decimal value of the type with no leading zeros. The rdata,
3853N/A if present, will be parsed using the UNKNOWN rdata format,
3853N/A (<backslash> <hash> <space> <length>
3853N/A <space> <hexstring>).
3853N/A The <
code class="option">-T</
code> and <
code class="option">-P</
code> options print out
3853N/A lists of non-meta types for which the type-specific presentation
3853N/A formats are known. <
code class="option">-T</
code> prints out the list of
3853N/A IANA-assigned types. <
code class="option">-P</
code> prints out the list of
3853N/A private types specific to <
span><
strong class="command">named</
strong></
span>. These options
3853N/A may be combined. <
span><
strong class="command">nsupdate</
strong></
span> will exit after the
3853N/A<
div class="refsect1" lang="en">
3853N/A<
a name="id2655721"></
a><
h2>INPUT FORMAT</
h2>
3853N/A<
p><
span><
strong class="command">nsupdate</
strong></
span>
3853N/A <
em class="parameter"><
code>filename</
code></
em>
3853N/A Each command is supplied on exactly one line of input.
3853N/A Some commands are for administrative purposes.
3853N/A The others are either update instructions or prerequisite checks on the
3853N/A These checks set conditions that some name or set of
3853N/A resource records (RRset) either exists or is absent from the zone.
3853N/A These conditions must be met if the entire update request is to succeed.
3853N/A Updates will be rejected if the tests for the prerequisite conditions
3853N/A Every update request consists of zero or more prerequisites
3853N/A This allows a suitably authenticated update request to proceed if some
3853N/A specified resource records are present or missing from the zone.
3853N/A A blank input line (or the <
span><
strong class="command">send</
strong></
span> command)
3853N/A accumulated commands to be sent as one Dynamic DNS update request to the
3853N/A The command formats and their meaning are as follows:
3853N/A<
div class="variablelist"><
dl>
3853N/A <
span><
strong class="command">server</
strong></
span>
3853N/A Sends all dynamic update requests to the name server
3853N/A <
em class="parameter"><
code>servername</
code></
em>.
3853N/A When no server statement is provided,
3853N/A <
span><
strong class="command">nsupdate</
strong></
span>
4165N/A will send updates to the master server of the correct zone.
3853N/A The MNAME field of that zone's SOA record will identify the
3853N/A <
em class="parameter"><
code>port</
code></
em>
3853N/A <
em class="parameter"><
code>servername</
code></
em>
3853N/A where the dynamic update requests get sent.
3853N/A If no port number is specified, the default DNS port number of
3853N/A <
span><
strong class="command">local</
strong></
span>
4876N/A Sends all dynamic update requests using the local
3853N/A <
em class="parameter"><
code>address</
code></
em>.
3853N/A When no local statement is provided,
3853N/A <
span><
strong class="command">nsupdate</
strong></
span>
3853N/A will send updates using an address and port chosen by the
3853N/A <
em class="parameter"><
code>port</
code></
em>
3853N/A can additionally be used to make requests come from a specific
3853N/A If no port number is specified, the system will assign one.
3853N/A <
span><
strong class="command">zone</
strong></
span>
3853N/A Specifies that all updates are to be made to the zone
3853N/A <
em class="parameter"><
code>zonename</
code></
em>.
3853N/A <
em class="parameter"><
code>zone</
code></
em>
3853N/A <
span><
strong class="command">nsupdate</
strong></
span>
3853N/A will attempt determine the correct zone to update based on the
3853N/A <
span><
strong class="command">class</
strong></
span>
3853N/A If no <
em class="parameter"><
code>class</
code></
em> is specified, the
3853N/A <
em class="parameter"><
code>IN</
code></
em>.
3853N/A <
span><
strong class="command">ttl</
strong></
span>
3853N/A Specify the default time to live for records to be added.
3853N/A The value <
em class="parameter"><
code>none</
code></
em> will clear the default
3853N/A <
span><
strong class="command">key</
strong></
span>
3853N/A Specifies that all updates are to be TSIG-signed using the
3853N/A <
em class="parameter"><
code>keyname</
code></
em> <
em class="parameter"><
code>keysecret</
code></
em> pair.
3853N/A The <
span><
strong class="command">key</
strong></
span> command
4676N/A overrides any key specified on the command line via
3853N/A <
code class="option">-y</
code> or <
code class="option">-k</
code>.
3853N/A <
span><
strong class="command">gsstsig</
strong></
span>
Use GSS-TSIG to sign the updated. This is equivalent to
specifying <
code class="option">-g</
code> on the commandline.
<
span><
strong class="command">oldgsstsig</
strong></
span>
Use the Windows 2000 version of GSS-TSIG to sign the updated.
This is equivalent to specifying <
code class="option">-o</
code> on the
<
span><
strong class="command">realm</
strong></
span>
{[<
span class="optional">realm_name</
span>]}
When using GSS-TSIG use <
em class="parameter"><
code>realm_name</
code></
em> rather
than the default realm in <
code class="filename">
krb5.conf</
code>. If no
realm is specified the saved realm is cleared.
<
span><
strong class="command">[<
span class="optional">prereq</
span>] nxdomain</
strong></
span>
Requires that no resource record of any type exists with name
<
em class="parameter"><
code>domain-name</
code></
em>.
<
span><
strong class="command">[<
span class="optional">prereq</
span>] yxdomain</
strong></
span>
<
em class="parameter"><
code>domain-name</
code></
em>
exists (has as at least one resource record, of any type).
<
span><
strong class="command">[<
span class="optional">prereq</
span>] nxrrset</
strong></
span>
Requires that no resource record exists of the specified
<
em class="parameter"><
code>type</
code></
em>,
<
em class="parameter"><
code>class</
code></
em>
<
em class="parameter"><
code>domain-name</
code></
em>.
<
em class="parameter"><
code>class</
code></
em>
is omitted, IN (internet) is assumed.
<
span><
strong class="command">[<
span class="optional">prereq</
span>] yxrrset</
strong></
span>
This requires that a resource record of the specified
<
em class="parameter"><
code>type</
code></
em>,
<
em class="parameter"><
code>class</
code></
em>
<
em class="parameter"><
code>domain-name</
code></
em>
<
em class="parameter"><
code>class</
code></
em>
is omitted, IN (internet) is assumed.
<
span><
strong class="command">[<
span class="optional">prereq</
span>] yxrrset</
strong></
span>
<
em class="parameter"><
code>data</
code></
em>
from each set of prerequisites of this form
<
em class="parameter"><
code>type</
code></
em>,
<
em class="parameter"><
code>class</
code></
em>,
<
em class="parameter"><
code>domain-name</
code></
em>
are combined to form a set of RRs. This set of RRs must
exactly match the set of RRs existing in the zone at the
<
em class="parameter"><
code>type</
code></
em>,
<
em class="parameter"><
code>class</
code></
em>,
<
em class="parameter"><
code>domain-name</
code></
em>.
<
em class="parameter"><
code>data</
code></
em>
are written in the standard text representation of the resource
<
span><
strong class="command">[<
span class="optional">update</
span>] del[<
span class="optional">ete</
span>]</
strong></
span>
Deletes any resource records named
<
em class="parameter"><
code>domain-name</
code></
em>.
<
em class="parameter"><
code>type</
code></
em>
<
em class="parameter"><
code>data</
code></
em>
is provided, only matching resource records will be removed.
The internet class is assumed if
<
em class="parameter"><
code>class</
code></
em>
<
em class="parameter"><
code>ttl</
code></
em>
is ignored, and is only allowed for compatibility.
<
span><
strong class="command">[<
span class="optional">update</
span>] add</
strong></
span>
Adds a new resource record with the specified
<
em class="parameter"><
code>ttl</
code></
em>,
<
em class="parameter"><
code>class</
code></
em>
<
em class="parameter"><
code>data</
code></
em>.
<
span><
strong class="command">show</
strong></
span>
Displays the current message, containing all of the
updates specified since the last send.
<
span><
strong class="command">send</
strong></
span>
Sends the current message. This is equivalent to entering a
<
span><
strong class="command">answer</
strong></
span>
<
span><
strong class="command">debug</
strong></
span>
Lines beginning with a semicolon are comments and are ignored.
<
div class="refsect1" lang="en">
<
a name="id2682933"></
a><
h2>EXAMPLES</
h2>
The examples below show how
<
span><
strong class="command">nsupdate</
strong></
span>
could be used to insert and delete resource records from the
Notice that the input in each example contains a trailing blank line so
a group of commands are sent as one dynamic update request to the
<
pre class="programlisting">
with IP address 172.16.1.1 is added.
The newly-added record has a 1 day TTL (86400 seconds).
<
pre class="programlisting">
The prerequisite condition gets the name server to check that there
are no resource records of any type for
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.)
<
div class="refsect1" lang="en">
<
a name="id2682983"></
a><
h2>FILES</
h2>
<
div class="variablelist"><
dl>
<
dt><
span class="term"><
code class="constant">/
etc/
resolv.conf</
code></
span></
dt>
used to identify default name server
sets the default TSIG key for use in local-only mode
<
dt><
span class="term"><
code class="constant">K{name}.+157.+{random}.key</
code></
span></
dt>
base-64 encoding of HMAC-MD5 key created by
<
span class="citerefentry"><
span class="refentrytitle">dnssec-keygen</
span>(8)</
span>.
<
dt><
span class="term"><
code class="constant">K{name}.+157.+{random}.private</
code></
span></
dt>
base-64 encoding of HMAC-MD5 key created by
<
span class="citerefentry"><
span class="refentrytitle">dnssec-keygen</
span>(8)</
span>.
<
div class="refsect1" lang="en">
<
a name="id2683066"></
a><
h2>SEE ALSO</
h2>
<
em class="citetitle">RFC 2136</
em>,
<
em class="citetitle">RFC 3007</
em>,
<
em class="citetitle">RFC 2104</
em>,
<
em class="citetitle">RFC 2845</
em>,
<
em class="citetitle">RFC 1034</
em>,
<
em class="citetitle">RFC 2535</
em>,
<
em class="citetitle">RFC 2931</
em>,
<
span class="citerefentry"><
span class="refentrytitle">named</
span>(8)</
span>,
<
span class="citerefentry"><
span class="refentrytitle">ddns-confgen</
span>(8)</
span>,
<
span class="citerefentry"><
span class="refentrytitle">dnssec-keygen</
span>(8)</
span>.
<
div class="refsect1" lang="en">
<
a name="id2683124"></
a><
h2>BUGS</
h2>
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
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