nsupdate.html 24.3 KB
Newer Older
1
<!--
Automatic Updater's avatar
regen  
Automatic Updater committed
2
 - Copyright (C) 2004-2009 Internet Systems Consortium, Inc. ("ISC")
Mark Andrews's avatar
regen  
Mark Andrews committed
3
 - Copyright (C) 2000-2003 Internet Software Consortium.
Rob Austein's avatar
regen  
Rob Austein committed
4
 - 
Automatic Updater's avatar
regen  
Automatic Updater committed
5
 - Permission to use, copy, modify, and/or distribute this software for any
6 7
 - purpose with or without fee is hereby granted, provided that the above
 - copyright notice and this permission notice appear in all copies.
Rob Austein's avatar
regen  
Rob Austein committed
8
 - 
Mark Andrews's avatar
Mark Andrews committed
9 10
 - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
Rob Austein's avatar
regen  
Rob Austein committed
11
 - AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
Mark Andrews's avatar
Mark Andrews committed
12 13 14 15
 - INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 - LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 - OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 - PERFORMANCE OF THIS SOFTWARE.
16
-->
Automatic Updater's avatar
regen  
Automatic Updater committed
17
<!-- $Id: nsupdate.html,v 1.47 2009/08/27 01:14:39 tbox Exp $ -->
Rob Austein's avatar
regen  
Rob Austein committed
18 19 20 21
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>nsupdate</title>
Automatic Updater's avatar
regen  
Automatic Updater committed
22
<meta name="generator" content="DocBook XSL Stylesheets V1.71.1">
Rob Austein's avatar
regen  
Rob Austein committed
23 24
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry" lang="en">
Automatic Updater's avatar
regen  
Automatic Updater committed
25
<a name="man.nsupdate"></a><div class="titlepage"></div>
Rob Austein's avatar
regen  
Rob Austein committed
26 27
<div class="refnamediv">
<h2>Name</h2>
Automatic Updater's avatar
regen  
Automatic Updater committed
28
<p><span class="application">nsupdate</span> &#8212; Dynamic DNS update utility</p>
Rob Austein's avatar
regen  
Rob Austein committed
29 30 31
</div>
<div class="refsynopsisdiv">
<h2>Synopsis</h2>
Automatic Updater's avatar
regen  
Automatic Updater committed
32
<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>] [filename]</p></div>
Rob Austein's avatar
regen  
Rob Austein committed
33 34
</div>
<div class="refsect1" lang="en">
Automatic Updater's avatar
regen  
Automatic Updater committed
35
<a name="id2543453"></a><h2>DESCRIPTION</h2>
Rob Austein's avatar
regen  
Rob Austein committed
36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67
<p><span><strong class="command">nsupdate</strong></span>
      is used to submit Dynamic DNS Update requests as defined in RFC2136
      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.
    </p>
<p>
      Zones that are under dynamic control via
      <span><strong class="command">nsupdate</strong></span>
      or a DHCP server should not be edited by hand.
      Manual edits could
      conflict with dynamic updates and cause data to be lost.
    </p>
<p>
      The resource records that are dynamically added or removed with
      <span><strong class="command">nsupdate</strong></span>
      have to be in the same zone.
      Requests are sent to the zone's master server.
      This is identified by the MNAME field of the zone's SOA record.
    </p>
<p>
      The
      <code class="option">-d</code>
      option makes
      <span><strong class="command">nsupdate</strong></span>
      operate in debug mode.
      This provides tracing information about the update requests that are
      made and the replies received from the name server.
    </p>
Automatic Updater's avatar
regen  
Automatic Updater committed
68 69 70 71
<p>
      The <code class="option">-D</code> option makes <span><strong class="command">nsupdate</strong></span>
      report additional debugging information to <code class="option">-d</code>.
    </p>
72 73 74 75
<p>
      The <code class="option">-L</code> option with an integer argument of zero or
      higher sets the logging debug level.  If zero, logging is disabled.
    </p>
Rob Austein's avatar
regen  
Rob Austein committed
76
<p>
Automatic Updater's avatar
regen  
Automatic Updater committed
77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95
      Transaction signatures can be used to authenticate the Dynamic
      DNS updates.  These use the TSIG resource record type described
      in RFC2845 or the SIG(0) record described in RFC3535 and
      RFC2931 or GSS-TSIG as described in RFC3645.  TSIG relies on
      a shared secret that should only be known to
      <span><strong class="command">nsupdate</strong></span> and the name server.  Currently,
      the only supported encryption algorithm for TSIG is HMAC-MD5,
      which is defined in RFC 2104.  Once other algorithms are
      defined for TSIG, applications will need to ensure they select
      the appropriate algorithm as well as the key when authenticating
      each other.  For instance, suitable <span class="type">key</span> and
      <span class="type">server</span> statements would be added to
      <code class="filename">/etc/named.conf</code> so that the name server
      can associate the appropriate secret key and algorithm with
      the IP address of the client application that will be using
      TSIG authentication.  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.
      <span><strong class="command">nsupdate</strong></span> does not read
Rob Austein's avatar
regen  
Rob Austein committed
96
      <code class="filename">/etc/named.conf</code>.
Automatic Updater's avatar
regen  
Automatic Updater committed
97
      GSS-TSIG uses Kerberos credentials.
Rob Austein's avatar
regen  
Rob Austein committed
98 99
    </p>
<p><span><strong class="command">nsupdate</strong></span>
Mark Andrews's avatar
regen  
Mark Andrews committed
100 101 102
      uses the <code class="option">-y</code> or <code class="option">-k</code> option
      to provide the shared secret needed to generate a TSIG record
      for authenticating Dynamic DNS update requests, default type
103 104 105 106 107
      HMAC-MD5.  These options are mutually exclusive. 
    </p>
<p>
      When the <code class="option">-y</code> option is used, a signature is
      generated from
Mark Andrews's avatar
regen  
Mark Andrews committed
108 109
      [<span class="optional"><em class="parameter"><code>hmac:</code></em></span>]<em class="parameter"><code>keyname:secret.</code></em>
      <em class="parameter"><code>keyname</code></em> is the name of the key, and
110 111 112 113 114 115
      <em class="parameter"><code>secret</code></em> is the base64 encoded shared secret.
      Use of the <code class="option">-y</code> option is discouraged because the
      shared secret is supplied as a command line argument in clear text.
      This may be visible in the output from
      <span class="citerefentry"><span class="refentrytitle">ps</span>(1)</span>
      or in a history file maintained by the user's shell.
Rob Austein's avatar
regen  
Rob Austein committed
116 117
    </p>
<p>
118 119 120 121 122 123 124 125 126 127
      With the
      <code class="option">-k</code> option, <span><strong class="command">nsupdate</strong></span> reads
      the shared secret from the file <em class="parameter"><code>keyfile</code></em>.
      Keyfiles may be in two formats: a single file containing
      a <code class="filename">named.conf</code>-format <span><strong class="command">key</strong></span>
      statement, which may be generated automatically by
      <span><strong class="command">ddns-confgen</strong></span>, or a pair of files whose names are
      of the format <code class="filename">K{name}.+157.+{random}.key</code> and
      <code class="filename">K{name}.+157.+{random}.private</code>, which can be
      generated by <span><strong class="command">dnssec-keygen</strong></span>.
Rob Austein's avatar
regen  
Rob Austein committed
128 129 130 131
      The <code class="option">-k</code> may 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.
    </p>
Automatic Updater's avatar
regen  
Automatic Updater committed
132
<p>
133 134 135 136 137 138
      <span><strong class="command">nsupdate</strong></span> can be run in a local-host only mode
      using the <code class="option">-l</code> flag.  This sets the server address to
      localhost (disabling the <span><strong class="command">server</strong></span> so that the server
      address cannot be overridden).  Connections to the local server will
      use a TSIG key found in <code class="filename">/var/run/named/ddns.key</code>,
      which is automatically generated by <span><strong class="command">named</strong></span> if any
Automatic Updater's avatar
regen  
Automatic Updater committed
139 140 141
      local master zone has set <span><strong class="command">update-policy</strong></span> to
      <span><strong class="command">local</strong></span>.  The location of this key file can be
      overridden with the <code class="option">-k</code> option.
Automatic Updater's avatar
regen  
Automatic Updater committed
142
    </p>
Rob Austein's avatar
regen  
Rob Austein committed
143
<p>
144
      By default, <span><strong class="command">nsupdate</strong></span>
Rob Austein's avatar
regen  
Rob Austein committed
145 146 147 148 149 150 151 152 153
      uses UDP to send update requests to the name server unless they are too
      large to fit in a UDP request in which case TCP will be used.
      The
      <code class="option">-v</code>
      option makes
      <span><strong class="command">nsupdate</strong></span>
      use a TCP connection.
      This may be preferable when a batch of update requests is made.
    </p>
154 155 156 157
<p>
      The <code class="option">-p</code> sets the default port number to use for
      connections to a name server.  The default is 53.
    </p>
Rob Austein's avatar
regen  
Rob Austein committed
158
<p>
Mark Andrews's avatar
regen  
Mark Andrews committed
159
      The <code class="option">-t</code> option sets the maximum time an update request
Rob Austein's avatar
regen  
Rob Austein committed
160 161 162 163 164 165 166 167
      can
      take before it is aborted.  The default is 300 seconds.  Zero can be
      used
      to disable the timeout.
    </p>
<p>
      The <code class="option">-u</code> option sets the UDP retry interval.  The default
      is
Mark Andrews's avatar
regen  
Mark Andrews committed
168
      3 seconds.  If zero, the interval will be computed from the timeout
Rob Austein's avatar
regen  
Rob Austein committed
169 170 171 172 173 174
      interval
      and number of UDP retries.
    </p>
<p>
      The <code class="option">-r</code> option sets the number of UDP retries. The
      default is
Mark Andrews's avatar
regen  
Mark Andrews committed
175
      3.  If zero, only one update request will be made.
Rob Austein's avatar
regen  
Rob Austein committed
176
    </p>
Mark Andrews's avatar
regen  
Mark Andrews committed
177 178 179 180 181 182 183 184 185 186 187
<p>
      The <code class="option">-R <em class="replaceable"><code>randomdev</code></em></code> option
      specifies a source of randomness.  If the operating system
      does not provide a <code class="filename">/dev/random</code> or
      equivalent device, the default source of randomness is keyboard
      input.  <code class="filename">randomdev</code> specifies the name of
      a character device or file containing random data to be used
      instead of the default.  The special value
      <code class="filename">keyboard</code> indicates that keyboard input
      should be used.  This option may be specified multiple times.
    </p>
Rob Austein's avatar
regen  
Rob Austein committed
188 189
</div>
<div class="refsect1" lang="en">
Automatic Updater's avatar
regen  
Automatic Updater committed
190
<a name="id2543777"></a><h2>INPUT FORMAT</h2>
Rob Austein's avatar
regen  
Rob Austein committed
191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218
<p><span><strong class="command">nsupdate</strong></span>
      reads input from
      <em class="parameter"><code>filename</code></em>
      or standard input.
      Each command is supplied on exactly one line of input.
      Some commands are for administrative purposes.
      The 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 will be rejected if the tests for the prerequisite conditions
      fail.
    </p>
<p>
      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 present or missing from the zone.
      A blank input line (or the <span><strong class="command">send</strong></span> command)
      causes the
      accumulated commands to be sent as one Dynamic DNS update request to the
      name server.
    </p>
<p>
      The command formats and their meaning are as follows:
      </p>
<div class="variablelist"><dl>
Mark Andrews's avatar
regen  
Mark Andrews committed
219 220 221 222 223
<dt><span class="term">
              <span><strong class="command">server</strong></span>
               {servername}
               [port]
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240
<dd><p>
              Sends all dynamic update requests to the name server
              <em class="parameter"><code>servername</code></em>.
              When no server statement is provided,
              <span><strong class="command">nsupdate</strong></span>
              will send updates to the master server of the correct zone.
              The MNAME field of that zone's SOA record will identify the
              master
              server for that zone.
              <em class="parameter"><code>port</code></em>
              is the port number on
              <em class="parameter"><code>servername</code></em>
              where the dynamic update requests get sent.
              If no port number is specified, the default DNS port number of
              53 is
              used.
            </p></dd>
Mark Andrews's avatar
regen  
Mark Andrews committed
241 242 243 244 245
<dt><span class="term">
              <span><strong class="command">local</strong></span>
               {address}
               [port]
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
246 247 248
<dd><p>
              Sends all dynamic update requests using the local
              <em class="parameter"><code>address</code></em>.
Mark Andrews's avatar
regen  
Mark Andrews committed
249

Rob Austein's avatar
regen  
Rob Austein committed
250 251 252 253 254 255 256 257 258
              When no local statement is provided,
              <span><strong class="command">nsupdate</strong></span>
              will send updates using an address and port chosen by the
              system.
              <em class="parameter"><code>port</code></em>
              can additionally be used to make requests come from a specific
              port.
              If no port number is specified, the system will assign one.
            </p></dd>
Mark Andrews's avatar
regen  
Mark Andrews committed
259 260 261 262
<dt><span class="term">
              <span><strong class="command">zone</strong></span>
               {zonename}
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
263 264 265 266 267 268 269 270 271 272
<dd><p>
              Specifies that all updates are to be made to the zone
              <em class="parameter"><code>zonename</code></em>.
              If no
              <em class="parameter"><code>zone</code></em>
              statement is provided,
              <span><strong class="command">nsupdate</strong></span>
              will attempt determine the correct zone to update based on the
              rest of the input.
            </p></dd>
Mark Andrews's avatar
regen  
Mark Andrews committed
273 274 275 276
<dt><span class="term">
              <span><strong class="command">class</strong></span>
               {classname}
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
277 278
<dd><p>
              Specify the default class.
Mark Andrews's avatar
regen  
Mark Andrews committed
279
              If no <em class="parameter"><code>class</code></em> is specified, the
Rob Austein's avatar
regen  
Rob Austein committed
280 281 282
              default class is
              <em class="parameter"><code>IN</code></em>.
            </p></dd>
Automatic Updater's avatar
regen  
Automatic Updater committed
283 284 285 286 287 288 289 290 291
<dt><span class="term">
              <span><strong class="command">ttl</strong></span>
               {seconds}
            </span></dt>
<dd><p>
              Specify the default time to live for records to be added.
	      The value <em class="parameter"><code>none</code></em> will clear the default
	      ttl.
            </p></dd>
Mark Andrews's avatar
regen  
Mark Andrews committed
292 293 294 295 296
<dt><span class="term">
              <span><strong class="command">key</strong></span>
               {name}
               {secret}
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
297
<dd><p>
Mark Andrews's avatar
regen  
Mark Andrews committed
298
              Specifies that all updates are to be TSIG-signed using the
Rob Austein's avatar
regen  
Rob Austein committed
299 300 301 302 303
              <em class="parameter"><code>keyname</code></em> <em class="parameter"><code>keysecret</code></em> pair.
              The <span><strong class="command">key</strong></span> command
              overrides any key specified on the command line via
              <code class="option">-y</code> or <code class="option">-k</code>.
            </p></dd>
Mark Andrews's avatar
regen  
Mark Andrews committed
304 305 306 307
<dt><span class="term">
              <span><strong class="command">prereq nxdomain</strong></span>
               {domain-name}
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
308 309 310 311
<dd><p>
              Requires that no resource record of any type exists with name
              <em class="parameter"><code>domain-name</code></em>.
            </p></dd>
Mark Andrews's avatar
regen  
Mark Andrews committed
312 313 314 315
<dt><span class="term">
              <span><strong class="command">prereq yxdomain</strong></span>
               {domain-name}
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
316 317 318 319 320
<dd><p>
              Requires that
              <em class="parameter"><code>domain-name</code></em>
              exists (has as at least one resource record, of any type).
            </p></dd>
Mark Andrews's avatar
regen  
Mark Andrews committed
321 322 323 324 325 326
<dt><span class="term">
              <span><strong class="command">prereq nxrrset</strong></span>
               {domain-name}
               [class]
               {type}
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
327 328 329 330 331 332 333 334 335 336
<dd><p>
              Requires that no resource record exists of the specified
              <em class="parameter"><code>type</code></em>,
              <em class="parameter"><code>class</code></em>
              and
              <em class="parameter"><code>domain-name</code></em>.
              If
              <em class="parameter"><code>class</code></em>
              is omitted, IN (internet) is assumed.
            </p></dd>
Mark Andrews's avatar
regen  
Mark Andrews committed
337 338 339 340 341 342
<dt><span class="term">
              <span><strong class="command">prereq yxrrset</strong></span>
               {domain-name}
               [class]
               {type}
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
343 344 345 346 347 348 349 350 351 352 353
<dd><p>
              This requires that a resource record of the specified
              <em class="parameter"><code>type</code></em>,
              <em class="parameter"><code>class</code></em>
              and
              <em class="parameter"><code>domain-name</code></em>
              must exist.
              If
              <em class="parameter"><code>class</code></em>
              is omitted, IN (internet) is assumed.
            </p></dd>
Mark Andrews's avatar
regen  
Mark Andrews committed
354 355 356 357 358 359 360
<dt><span class="term">
              <span><strong class="command">prereq yxrrset</strong></span>
               {domain-name}
               [class]
               {type}
               {data...}
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382
<dd><p>
              The
              <em class="parameter"><code>data</code></em>
              from each set of prerequisites of this form
              sharing a common
              <em class="parameter"><code>type</code></em>,
              <em class="parameter"><code>class</code></em>,
              and
              <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
              given
              <em class="parameter"><code>type</code></em>,
              <em class="parameter"><code>class</code></em>,
              and
              <em class="parameter"><code>domain-name</code></em>.
              The
              <em class="parameter"><code>data</code></em>
              are written in the standard text representation of the resource
              record's
              RDATA.
            </p></dd>
Mark Andrews's avatar
regen  
Mark Andrews committed
383 384 385 386 387
<dt><span class="term">
              <span><strong class="command">update delete</strong></span>
               {domain-name}
               [ttl]
               [class]
Automatic Updater's avatar
regen  
Automatic Updater committed
388
               [type [data...]]
Mark Andrews's avatar
regen  
Mark Andrews committed
389
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
390 391 392 393 394 395 396 397 398 399 400 401 402 403
<dd><p>
              Deletes any resource records named
              <em class="parameter"><code>domain-name</code></em>.
              If
              <em class="parameter"><code>type</code></em>
              and
              <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>
              is not supplied.  The
              <em class="parameter"><code>ttl</code></em>
              is ignored, and is only allowed for compatibility.
            </p></dd>
Mark Andrews's avatar
regen  
Mark Andrews committed
404 405 406 407 408 409 410 411
<dt><span class="term">
              <span><strong class="command">update add</strong></span>
               {domain-name}
               {ttl}
               [class]
               {type}
               {data...}
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
412 413 414 415 416 417 418
<dd><p>
              Adds a new resource record with the specified
              <em class="parameter"><code>ttl</code></em>,
              <em class="parameter"><code>class</code></em>
              and
              <em class="parameter"><code>data</code></em>.
            </p></dd>
Mark Andrews's avatar
regen  
Mark Andrews committed
419 420 421
<dt><span class="term">
              <span><strong class="command">show</strong></span>
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
422 423 424 425 426
<dd><p>
              Displays the current message, containing all of the
              prerequisites and
              updates specified since the last send.
            </p></dd>
Mark Andrews's avatar
regen  
Mark Andrews committed
427 428 429
<dt><span class="term">
              <span><strong class="command">send</strong></span>
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
430 431 432 433
<dd><p>
              Sends the current message.  This is equivalent to entering a
              blank line.
            </p></dd>
Mark Andrews's avatar
regen  
Mark Andrews committed
434 435 436
<dt><span class="term">
              <span><strong class="command">answer</strong></span>
            </span></dt>
Rob Austein's avatar
regen  
Rob Austein committed
437 438 439
<dd><p>
              Displays the answer.
            </p></dd>
Automatic Updater's avatar
regen  
Automatic Updater committed
440 441 442 443 444 445
<dt><span class="term">
              <span><strong class="command">debug</strong></span>
            </span></dt>
<dd><p>
              Turn on debugging.
            </p></dd>
Rob Austein's avatar
regen  
Rob Austein committed
446 447 448 449 450 451 452 453
</dl></div>
<p>
    </p>
<p>
      Lines beginning with a semicolon are comments and are ignored.
    </p>
</div>
<div class="refsect1" lang="en">
Automatic Updater's avatar
regen  
Automatic Updater committed
454
<a name="id2544617"></a><h2>EXAMPLES</h2>
Rob Austein's avatar
regen  
Rob Austein committed
455 456 457 458 459 460 461 462 463 464 465
<p>
      The examples below show how
      <span><strong class="command">nsupdate</strong></span>
      could be used to insert and delete resource records from the
      <span class="type">example.com</span>
      zone.
      Notice that the input in each example contains a trailing blank line so
      that
      a group of commands are sent as one dynamic update request to the
      master name server for
      <span class="type">example.com</span>.
Mark Andrews's avatar
regen  
Mark Andrews committed
466

Rob Austein's avatar
regen  
Rob Austein committed
467 468 469 470 471 472 473 474 475 476 477 478 479
      </p>
<pre class="programlisting">
# nsupdate
&gt; update delete oldhost.example.com A
&gt; update add newhost.example.com 86400 A 172.16.1.1
&gt; send
</pre>
<p>
    </p>
<p>
      Any A records for
      <span class="type">oldhost.example.com</span>
      are deleted.
Mark Andrews's avatar
regen  
Mark Andrews committed
480
      And an A record for
Rob Austein's avatar
regen  
Rob Austein committed
481
      <span class="type">newhost.example.com</span>
Mark Andrews's avatar
regen  
Mark Andrews committed
482 483
      with IP address 172.16.1.1 is added.
      The newly-added record has a 1 day TTL (86400 seconds).
Rob Austein's avatar
regen  
Rob Austein committed
484 485 486 487 488 489 490 491 492 493 494 495 496
      </p>
<pre class="programlisting">
# nsupdate
&gt; prereq nxdomain nickname.example.com
&gt; update add nickname.example.com 86400 CNAME somehost.example.com
&gt; send
</pre>
<p>
    </p>
<p>
      The prerequisite condition gets the name server to check that there
      are no resource records of any type for
      <span class="type">nickname.example.com</span>.
497

Rob Austein's avatar
regen  
Rob Austein committed
498 499 500 501 502 503 504 505 506 507
      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 RFC1034 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 RFC2535 to allow CNAMEs to have
      RRSIG, DNSKEY and NSEC records.)
    </p>
</div>
<div class="refsect1" lang="en">
Automatic Updater's avatar
regen  
Automatic Updater committed
508
<a name="id2544661"></a><h2>FILES</h2>
Rob Austein's avatar
regen  
Rob Austein committed
509 510 511 512 513
<div class="variablelist"><dl>
<dt><span class="term"><code class="constant">/etc/resolv.conf</code></span></dt>
<dd><p>
            used to identify default name server
          </p></dd>
514 515 516 517
<dt><span class="term"><code class="constant">/var/run/named/ddns.key</code></span></dt>
<dd><p>
            sets the default TSIG key for use in local-only mode
          </p></dd>
Rob Austein's avatar
regen  
Rob Austein committed
518 519 520 521 522 523 524 525 526 527 528 529 530
<dt><span class="term"><code class="constant">K{name}.+157.+{random}.key</code></span></dt>
<dd><p>
            base-64 encoding of HMAC-MD5 key created by
            <span class="citerefentry"><span class="refentrytitle">dnssec-keygen</span>(8)</span>.
          </p></dd>
<dt><span class="term"><code class="constant">K{name}.+157.+{random}.private</code></span></dt>
<dd><p>
            base-64 encoding of HMAC-MD5 key created by
            <span class="citerefentry"><span class="refentrytitle">dnssec-keygen</span>(8)</span>.
          </p></dd>
</dl></div>
</div>
<div class="refsect1" lang="en">
Automatic Updater's avatar
regen  
Automatic Updater committed
531
<a name="id2544744"></a><h2>SEE ALSO</h2>
Rob Austein's avatar
regen  
Rob Austein committed
532 533 534 535 536 537 538 539
<p><span class="citerefentry"><span class="refentrytitle">RFC2136</span></span>,
      <span class="citerefentry"><span class="refentrytitle">RFC3007</span></span>,
      <span class="citerefentry"><span class="refentrytitle">RFC2104</span></span>,
      <span class="citerefentry"><span class="refentrytitle">RFC2845</span></span>,
      <span class="citerefentry"><span class="refentrytitle">RFC1034</span></span>,
      <span class="citerefentry"><span class="refentrytitle">RFC2535</span></span>,
      <span class="citerefentry"><span class="refentrytitle">RFC2931</span></span>,
      <span class="citerefentry"><span class="refentrytitle">named</span>(8)</span>,
540
      <span class="citerefentry"><span class="refentrytitle">ddns-confgen</span>(8)</span>,
Rob Austein's avatar
regen  
Rob Austein committed
541 542 543 544
      <span class="citerefentry"><span class="refentrytitle">dnssec-keygen</span>(8)</span>.
    </p>
</div>
<div class="refsect1" lang="en">
Automatic Updater's avatar
regen  
Automatic Updater committed
545
<a name="id2542161"></a><h2>BUGS</h2>
Rob Austein's avatar
regen  
Rob Austein committed
546 547 548 549 550 551 552 553 554
<p>
      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.
    </p>
</div>
</div></body>
</html>