nslookup.html revision e21a2904f02a03fa06b6db04d348f65fe9c67b2b
3b4098640dd85040270f39b9a5ee5e22de99d3d6Mark Andrews - Copyright (C) 2004-2006 Internet Systems Consortium, Inc. ("ISC")
3eb9ec750c9088869170dda63e8899b2ba462823Mark Andrews - Permission to use, copy, modify, and distribute this software for any
3eb9ec750c9088869170dda63e8899b2ba462823Mark Andrews - purpose with or without fee is hereby granted, provided that the above
3eb9ec750c9088869170dda63e8899b2ba462823Mark Andrews - copyright notice and this permission notice appear in all copies.
3eb9ec750c9088869170dda63e8899b2ba462823Mark Andrews - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
3eb9ec750c9088869170dda63e8899b2ba462823Mark Andrews - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
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e21a2904f02a03fa06b6db04d348f65fe9c67b2bMark Andrews<!-- $Id: nslookup.html,v 1.16 2006/12/12 01:45:20 marka Exp $ -->
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60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry" lang="en">
e21a2904f02a03fa06b6db04d348f65fe9c67b2bMark Andrews<a name="id2476423"></a><div class="titlepage"></div>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<p>nslookup — query Internet name servers interactively</p>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<div class="cmdsynopsis"><p><code class="command">nslookup</code> [<code class="option">-option</code>] [name | -] [server]</p></div>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<p><span><strong class="command">Nslookup</strong></span>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein is a program to query Internet domain name servers. <span><strong class="command">Nslookup</strong></span>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein has two modes: interactive and non-interactive. Interactive mode allows
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the user to query name servers for information about various hosts and
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein domains or to print a list of hosts in a domain. Non-interactive mode
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein used to print just the name and requested information for a host or
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Interactive mode is entered in the following cases:
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein when no arguments are given (the default name server will be used)
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein when the first argument is a hyphen (-) and the second argument is
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the host name or Internet address of a name server.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Non-interactive mode is used when the name or Internet address of the
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein host to be looked up is given as the first argument. The optional second
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein argument specifies the host name or address of a name server.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Options can also be specified on the command line if they precede the
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein arguments and are prefixed with a hyphen. For example, to
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein change the default query type to host information, and the initial
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein timeout to 10 seconds, type:
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<div class="informalexample"><pre class="programlisting">
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austeinnslookup -query=hinfo -timeout=10
e21a2904f02a03fa06b6db04d348f65fe9c67b2bMark Andrews<a name="id2543668"></a><h2>INTERACTIVE COMMANDS</h2>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term">host [<span class="optional">server</span>]</span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Look up information for host using the current default server or
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein using server, if specified. If host is an Internet address and
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the query type is A or PTR, the name of the host is returned.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein If host is a name and does not have a trailing period, the
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein search list is used to qualify the name.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein To look up a host not in the current domain, append a period to
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">server</code> <em class="replaceable"><code>domain</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">lserver</code> <em class="replaceable"><code>domain</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Change the default server to <em class="replaceable"><code>domain</code></em>; <code class="constant">lserver</code> uses the initial
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein server to look up information about <em class="replaceable"><code>domain</code></em>, while <code class="constant">server</code> uses
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the current default server. If an authoritative answer can't be
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein found, the names of servers that might have the answer are
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">root</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein not implemented
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">finger</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein not implemented
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">ls</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein not implemented
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">view</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein not implemented
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">help</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein not implemented
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">?</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein not implemented
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">exit</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Exits the program.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">set</code>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <em class="replaceable"><code>keyword[<span class="optional">=value</span>]</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein This command is used to change state information that affects
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the lookups. Valid keywords are:
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">all</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Prints the current values of the frequently used
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein options to <span><strong class="command">set</strong></span>.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Information about the current default
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein server and host is also printed.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">class=</code><em class="replaceable"><code>value</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Change the query class to one of:
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">IN</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the Internet class
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">CH</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the Chaos class
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">HS</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the Hesiod class
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">ANY</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein The class specifies the protocol group of the information.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein (Default = IN; abbreviation = cl)
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <em class="replaceable"><code>[<span class="optional">no</span>]</code></em>debug</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Turn debugging mode on. A lot more information is
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein printed about the packet sent to the server and the
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein resulting answer.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein (Default = nodebug; abbreviation = [<span class="optional">no</span>]deb)
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <em class="replaceable"><code>[<span class="optional">no</span>]</code></em>d2</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Turn debugging mode on. A lot more information is
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein printed about the packet sent to the server and the
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein resulting answer.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein (Default = nod2)
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">domain=</code><em class="replaceable"><code>name</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Sets the search list to <em class="replaceable"><code>name</code></em>.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <em class="replaceable"><code>[<span class="optional">no</span>]</code></em>search</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein If the lookup request contains at least one period but
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein doesn't end with a trailing period, append the domain
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein names in the domain search list to the request until an
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein answer is received.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein (Default = search)
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">port=</code><em class="replaceable"><code>value</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Change the default TCP/UDP name server port to <em class="replaceable"><code>value</code></em>.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein (Default = 53; abbreviation = po)
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">querytype=</code><em class="replaceable"><code>value</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">type=</code><em class="replaceable"><code>value</code></em></span></dt>
3b4098640dd85040270f39b9a5ee5e22de99d3d6Mark Andrews Change the type of the information query.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein (Default = A; abbreviations = q, ty)
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <em class="replaceable"><code>[<span class="optional">no</span>]</code></em>recurse</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Tell the name server to query other servers if it does not
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein information.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein (Default = recurse; abbreviation = [no]rec)
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">retry=</code><em class="replaceable"><code>number</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Set the number of retries to number.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term"><code class="constant">timeout=</code><em class="replaceable"><code>number</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Change the initial timeout interval for waiting for a
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein reply to number seconds.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <em class="replaceable"><code>[<span class="optional">no</span>]</code></em>vc</code></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Always use a virtual circuit when sending requests to the
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein (Default = novc)
a057e8e33baa5fa369be28a9680585200ce3ff73Mark Andrews <em class="replaceable"><code>[<span class="optional">no</span>]</code></em>fail</code></span></dt>
a057e8e33baa5fa369be28a9680585200ce3ff73Mark Andrews Try the next nameserver if a nameserver responds with
a057e8e33baa5fa369be28a9680585200ce3ff73Mark Andrews SERVFAIL or a referral (nofail) or terminate query
a057e8e33baa5fa369be28a9680585200ce3ff73Mark Andrews (fail) on such a response.
a057e8e33baa5fa369be28a9680585200ce3ff73Mark Andrews (Default = nofail)
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<p><code class="filename">/etc/resolv.conf</code>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<p><span class="citerefentry"><span class="refentrytitle">dig</span>(1)</span>,
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <span class="citerefentry"><span class="refentrytitle">host</span>(1)</span>,
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <span class="citerefentry"><span class="refentrytitle">named</span>(8)</span>.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Andrew Cherenson