nsupdate.docbook

非常好的dns解析软件

            <para>
              Requires that no resource record of any type exists with name
              <parameter>domain-name</parameter>.
            </para>
          </listitem>
        </varlistentry>


        <varlistentry>
          <term>
              <command>prereq yxdomain</command>
              <arg choice="req">domain-name</arg>
            </term>
          <listitem>
            <para>
              Requires that
              <parameter>domain-name</parameter>
              exists (has as at least one resource record, of any type).
            </para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>
              <command>prereq nxrrset</command>
              <arg choice="req">domain-name</arg>
              <arg choice="opt">class</arg>
              <arg choice="req">type</arg>
            </term>
          <listitem>
            <para>
              Requires that no resource record exists of the specified
              <parameter>type</parameter>,
              <parameter>class</parameter>
              and
              <parameter>domain-name</parameter>.
              If
              <parameter>class</parameter>
              is omitted, IN (internet) is assumed.
            </para>
          </listitem>
        </varlistentry>


        <varlistentry>
          <term>
              <command>prereq yxrrset</command>
              <arg choice="req">domain-name</arg>
              <arg choice="opt">class</arg>
              <arg choice="req">type</arg>
            </term>
          <listitem>
            <para>
              This requires that a resource record of the specified
              <parameter>type</parameter>,
              <parameter>class</parameter>
              and
              <parameter>domain-name</parameter>
              must exist.
              If
              <parameter>class</parameter>
              is omitted, IN (internet) is assumed.
            </para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>
              <command>prereq yxrrset</command>
              <arg choice="req">domain-name</arg>
              <arg choice="opt">class</arg>
              <arg choice="req">type</arg>
              <arg choice="req" rep="repeat">data</arg>
            </term>
          <listitem>
            <para>
              The
              <parameter>data</parameter>
              from each set of prerequisites of this form
              sharing a common
              <parameter>type</parameter>,
              <parameter>class</parameter>,
              and
              <parameter>domain-name</parameter>
              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
              <parameter>type</parameter>,
              <parameter>class</parameter>,
              and
              <parameter>domain-name</parameter>.
              The
              <parameter>data</parameter>
              are written in the standard text representation of the resource
              record's
              RDATA.
            </para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>
              <command>update delete</command>
              <arg choice="req">domain-name</arg>
              <arg choice="opt">ttl</arg>
              <arg choice="opt">class</arg>
              <arg choice="opt">type <arg choice="opt" rep="repeat">data</arg></arg>
            </term>
          <listitem>
            <para>
              Deletes any resource records named
              <parameter>domain-name</parameter>.
              If
              <parameter>type</parameter>
              and
              <parameter>data</parameter>
              is provided, only matching resource records will be removed.
              The internet class is assumed if
              <parameter>class</parameter>
              is not supplied.  The
              <parameter>ttl</parameter>
              is ignored, and is only allowed for compatibility.
            </para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>
              <command>update add</command>
              <arg choice="req">domain-name</arg>
              <arg choice="req">ttl</arg>
              <arg choice="opt">class</arg>
              <arg choice="req">type</arg>
              <arg choice="req" rep="repeat">data</arg>
            </term>
          <listitem>
            <para>
              Adds a new resource record with the specified
              <parameter>ttl</parameter>,
              <parameter>class</parameter>
              and
              <parameter>data</parameter>.
            </para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>
              <command>show</command>
            </term>
          <listitem>
            <para>
              Displays the current message, containing all of the
              prerequisites and
              updates specified since the last send.
            </para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>
              <command>send</command>
            </term>
          <listitem>
            <para>
              Sends the current message.  This is equivalent to entering a
              blank line.
            </para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>
              <command>answer</command>
            </term>
          <listitem>
            <para>
              Displays the answer.
            </para>
          </listitem>
        </varlistentry>

      </variablelist>
    </para>

    <para>
      Lines beginning with a semicolon are comments and are ignored.
    </para>

  </refsect1>

  <refsect1>
    <title>EXAMPLES</title>
    <para>
      The examples below show how
      <command>nsupdate</command>
      could be used to insert and delete resource records from the
      <type>example.com</type>
      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
      <type>example.com</type>.

      <programlisting>
# nsupdate
&gt; update delete oldhost.example.com A
&gt; update add newhost.example.com 86400 A 172.16.1.1
&gt; send
</programlisting>
    </para>
    <para>
      Any A records for
      <type>oldhost.example.com</type>
      are deleted.
      and an A record for
      <type>newhost.example.com</type>
      it IP address 172.16.1.1 is added.
      The newly-added record has a 1 day TTL (86400 seconds)
      <programlisting>
# nsupdate
&gt; prereq nxdomain nickname.example.com
&gt; update add nickname.example.com 86400 CNAME somehost.example.com
&gt; send
</programlisting>
    </para>
    <para>
      The prerequisite condition gets the name server to check that there
      are no resource records of any type for
      <type>nickname.example.com</type>.

      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.)
    </para>
  </refsect1>

  <refsect1>
    <title>FILES</title>

    <variablelist>
      <varlistentry>
        <term><constant>/etc/resolv.conf</constant></term>
        <listitem>
          <para>
            used to identify default name server
          </para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><constant>K{name}.+157.+{random}.key</constant></term>
        <listitem>
          <para>
            base-64 encoding of HMAC-MD5 key created by
            <citerefentry>
              <refentrytitle>dnssec-keygen</refentrytitle><manvolnum>8</manvolnum>
            </citerefentry>.
          </para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><constant>K{name}.+157.+{random}.private</constant></term>
        <listitem>
          <para>
            base-64 encoding of HMAC-MD5 key created by
            <citerefentry>
              <refentrytitle>dnssec-keygen</refentrytitle><manvolnum>8</manvolnum>
            </citerefentry>.
          </para>
        </listitem>
      </varlistentry>

    </variablelist>
  </refsect1>

  <refsect1>
    <title>SEE ALSO</title>
    <para><citerefentry>
        <refentrytitle>RFC2136</refentrytitle>
      </citerefentry>,
      <citerefentry>
        <refentrytitle>RFC3007</refentrytitle>
      </citerefentry>,
      <citerefentry>
        <refentrytitle>RFC2104</refentrytitle>
      </citerefentry>,
      <citerefentry>
        <refentrytitle>RFC2845</refentrytitle>
      </citerefentry>,
      <citerefentry>
        <refentrytitle>RFC1034</refentrytitle>
      </citerefentry>,
      <citerefentry>
        <refentrytitle>RFC2535</refentrytitle>
      </citerefentry>,
      <citerefentry>
        <refentrytitle>RFC2931</refentrytitle>
      </citerefentry>,
      <citerefentry>
        <refentrytitle>named</refentrytitle><manvolnum>8</manvolnum>
      </citerefentry>,
      <citerefentry>
        <refentrytitle>dnssec-keygen</refentrytitle><manvolnum>8</manvolnum>
      </citerefentry>.
    </para>

  </refsect1>
  <refsect1>
    <title>BUGS</title>
    <para>
      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.
    </para>
  </refsect1>
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