nsupdate.html

linux网络工具

<div class="cmdsynopsis"><p><code class="command">class</code>  {classname}</p></div>
</span></dt>
<dd><p>
Specify the default class.
If no <em class="parameter"><code>class</code></em> is specified the default class is
<em class="parameter"><code>IN</code></em>.
</p></dd>
<dt><span class="term">
<div class="cmdsynopsis"><p><code class="command">key</code>  {name} {secret}</p></div>
</span></dt>
<dd><p>
Specifies that all updates are to be TSIG signed using the
<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>
<dt><span class="term">
<div class="cmdsynopsis"><p><code class="command">prereq nxdomain</code>  {domain-name}</p></div>
</span></dt>
<dd><p>
Requires that no resource record of any type exists with name
<em class="parameter"><code>domain-name</code></em>.
</p></dd>
<dt><span class="term">
<div class="cmdsynopsis"><p><code class="command">prereq yxdomain</code>  {domain-name}</p></div>
</span></dt>
<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>
<dt><span class="term">
<div class="cmdsynopsis"><p><code class="command">prereq nxrrset</code>  {domain-name} [class] {type}</p></div>
</span></dt>
<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>
<dt><span class="term">
<div class="cmdsynopsis"><p><code class="command">prereq yxrrset</code>  {domain-name} [class] {type}</p></div>
</span></dt>
<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>
<dt><span class="term">
<div class="cmdsynopsis"><p><code class="command">prereq yxrrset</code>  {domain-name} [class] {type} {data...}</p></div>
</span></dt>
<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>
<dt><span class="term">
<div class="cmdsynopsis"><p><code class="command">update delete</code>  {domain-name} [ttl] [class] [type  [data...]]</p></div>
</span></dt>
<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>
<dt><span class="term">
<div class="cmdsynopsis"><p><code class="command">update add</code>  {domain-name} {ttl} [class] {type} {data...}</p></div>
</span></dt>
<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>
<dt><span class="term">
<div class="cmdsynopsis"><p><code class="command">show</code> </p></div>
</span></dt>
<dd><p>
Displays the current message, containing all of the prerequisites and
updates specified since the last send.
</p></dd>
<dt><span class="term">
<div class="cmdsynopsis"><p><code class="command">send</code> </p></div>
</span></dt>
<dd><p>
Sends the current message.  This is equivalent to entering a blank line.
</p></dd>
<dt><span class="term">
<div class="cmdsynopsis"><p><code class="command">answer</code> </p></div>
</span></dt>
<dd><p>
Displays the answer.
</p></dd>
</dl></div>
<p>
</p>
<p>
Lines beginning with a semicolon are comments and are ignored.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2526749"></a><h2>EXAMPLES</h2>
<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>.

</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.
and an A record for
<span class="type">newhost.example.com</span>
it IP address 172.16.1.1 is added.
The newly-added record has a 1 day TTL (86400 seconds)
</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>.

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">
<a name="id2526793"></a><h2>FILES</h2>
<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>
<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">
<a name="id2525155"></a><h2>SEE ALSO</h2>
<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>,
<span class="citerefentry"><span class="refentrytitle">dnssec-keygen</span>(8)</span>.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2525226"></a><h2>BUGS</h2>
<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>
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