nsupdate.docbook

非常好的dns解析软件

<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
               "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"
	       [<!ENTITY mdash "&#8212;">]>
<!--
 - Copyright (C) 2004-2007  Internet Systems Consortium, Inc. ("ISC")
 - Copyright (C) 2000-2003  Internet Software Consortium.
 -
 - Permission to use, copy, modify, and distribute this software for any
 - purpose with or without fee is hereby granted, provided that the above
 - copyright notice and this permission notice appear in all copies.
 -
 - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 - AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 - 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.
-->

<!-- $Id: nsupdate.docbook,v 1.18.18.8 2007/01/29 23:57:20 marka Exp $ -->
<refentry>
  <refentryinfo>
    <date>Jun 30, 2000</date>
  </refentryinfo>
  <refmeta>
    <refentrytitle>nsupdate</refentrytitle>
    <manvolnum>8</manvolnum>
    <refmiscinfo>BIND9</refmiscinfo>
  </refmeta>
  <refnamediv>
    <refname>nsupdate</refname>
    <refpurpose>Dynamic DNS update utility</refpurpose>
  </refnamediv>

  <docinfo>
    <copyright>
      <year>2004</year>
      <year>2005</year>
      <year>2006</year>
      <year>2007</year>
      <holder>Internet Systems Consortium, Inc. ("ISC")</holder>
    </copyright>
    <copyright>
      <year>2000</year>
      <year>2001</year>
      <year>2002</year>
      <year>2003</year>
      <holder>Internet Software Consortium.</holder>
    </copyright>
  </docinfo>

  <refsynopsisdiv>
    <cmdsynopsis>
      <command>nsupdate</command>
      <arg><option>-d</option></arg>
      <group>
        <arg><option>-y <replaceable class="parameter"><optional>hmac:</optional>keyname:secret</replaceable></option></arg>
        <arg><option>-k <replaceable class="parameter">keyfile</replaceable></option></arg>
      </group>
      <arg><option>-t <replaceable class="parameter">timeout</replaceable></option></arg>
      <arg><option>-u <replaceable class="parameter">udptimeout</replaceable></option></arg>
      <arg><option>-r <replaceable class="parameter">udpretries</replaceable></option></arg>
      <arg><option>-v</option></arg>
      <arg>filename</arg>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>DESCRIPTION</title>
    <para><command>nsupdate</command>
      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.
    </para>
    <para>
      Zones that are under dynamic control via
      <command>nsupdate</command>
      or a DHCP server should not be edited by hand.
      Manual edits could
      conflict with dynamic updates and cause data to be lost.
    </para>
    <para>
      The resource records that are dynamically added or removed with
      <command>nsupdate</command>
      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.
    </para>
    <para>
      The
      <option>-d</option>
      option makes
      <command>nsupdate</command>
      operate in debug mode.
      This provides tracing information about the update requests that are
      made and the replies received from the name server.
    </para>
    <para>
      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.
      TSIG relies on a shared secret that should only be known to
      <command>nsupdate</command> 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
      <type>key</type>
      and
      <type>server</type>
      statements would be added to
      <filename>/etc/named.conf</filename>
      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.
      <command>nsupdate</command>
      does not read
      <filename>/etc/named.conf</filename>.
    </para>
    <para><command>nsupdate</command>
      uses the <option>-y</option> or <option>-k</option> option
      to provide the shared secret needed to generate a TSIG record
      for authenticating Dynamic DNS update requests, default type
      HMAC-MD5.  These options are mutually exclusive.  With the
      <option>-k</option> option, <command>nsupdate</command> reads
      the shared secret from the file <parameter>keyfile</parameter>,
      whose name is of the form
      <filename>K{name}.+157.+{random}.private</filename>.  For
      historical reasons, the file
      <filename>K{name}.+157.+{random}.key</filename> must also be
      present.  When the <option>-y</option> option is used, a
      signature is generated from
      <optional><parameter>hmac:</parameter></optional><parameter>keyname:secret.</parameter>
      <parameter>keyname</parameter> is the name of the key, and
      <parameter>secret</parameter> is the base64 encoded shared
      secret.  Use of the <option>-y</option> 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
      <citerefentry>
	<refentrytitle>ps</refentrytitle><manvolnum>1</manvolnum>
      </citerefentry> or in a history file maintained by the user's
      shell.
    </para>
    <para>
      The <option>-k</option> 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.
    </para>
    <para>
      By default
      <command>nsupdate</command>
      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
      <option>-v</option>
      option makes
      <command>nsupdate</command>
      use a TCP connection.
      This may be preferable when a batch of update requests is made.
    </para>
    <para>
      The <option>-t</option> option sets the maximum time a update request
      can
      take before it is aborted.  The default is 300 seconds.  Zero can be
      used
      to disable the timeout.
    </para>
    <para>
      The <option>-u</option> option sets the UDP retry interval.  The default
      is
      3 seconds.  If zero the interval will be computed from the timeout
      interval
      and number of UDP retries.
    </para>
    <para>
      The <option>-r</option> option sets the number of UDP retries. The
      default is
      3.  If zero only one update request will be made.
    </para>
  </refsect1>

  <refsect1>
    <title>INPUT FORMAT</title>
    <para><command>nsupdate</command>
      reads input from
      <parameter>filename</parameter>
      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.
    </para>
    <para>
      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 <command>send</command> command)
      causes the
      accumulated commands to be sent as one Dynamic DNS update request to the
      name server.
    </para>
    <para>
      The command formats and their meaning are as follows:
      <variablelist>

        <varlistentry>
          <term>
              <command>server</command>
              <arg choice="req">servername</arg>
              <arg choice="opt">port</arg>
            </term>
          <listitem>
            <para>
              Sends all dynamic update requests to the name server
              <parameter>servername</parameter>.
              When no server statement is provided,
              <command>nsupdate</command>
              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.
              <parameter>port</parameter>
              is the port number on
              <parameter>servername</parameter>
              where the dynamic update requests get sent.
              If no port number is specified, the default DNS port number of
              53 is
              used.
            </para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>
              <command>local</command>
              <arg choice="req">address</arg>
              <arg choice="opt">port</arg>
            </term>
          <listitem>
            <para>
              Sends all dynamic update requests using the local
              <parameter>address</parameter>.

              When no local statement is provided,
              <command>nsupdate</command>
              will send updates using an address and port chosen by the
              system.
              <parameter>port</parameter>
              can additionally be used to make requests come from a specific
              port.
              If no port number is specified, the system will assign one.
            </para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>
              <command>zone</command>
              <arg choice="req">zonename</arg>
            </term>
          <listitem>
            <para>
              Specifies that all updates are to be made to the zone
              <parameter>zonename</parameter>.
              If no
              <parameter>zone</parameter>
              statement is provided,
              <command>nsupdate</command>
              will attempt determine the correct zone to update based on the
              rest of the input.
            </para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>
              <command>class</command>
              <arg choice="req">classname</arg>
            </term>
          <listitem>
            <para>
              Specify the default class.
              If no <parameter>class</parameter> is specified the
              default class is
              <parameter>IN</parameter>.
            </para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>
              <command>key</command>
              <arg choice="req">name</arg>
              <arg choice="req">secret</arg>
            </term>
          <listitem>
            <para>
              Specifies that all updates are to be TSIG signed using the
              <parameter>keyname</parameter> <parameter>keysecret</parameter> pair.
              The <command>key</command> command
              overrides any key specified on the command line via
              <option>-y</option> or <option>-k</option>.
            </para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>
              <command>prereq nxdomain</command>
              <arg choice="req">domain-name</arg>
            </term>
          <listitem>