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23 <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry" lang="en">
24 <a name="id2476276"></a><div class="titlepage"></div>
25 <div class="refnamediv">
27 <p>nslookup — query Internet name servers interactively</p>
29 <div class="refsynopsisdiv">
31 <div class="cmdsynopsis"><p><code class="command">nslookup</code> [<code class="option">-option</code>] [name | -] [server]</p></div>
33 <div class="refsect1" lang="en">
34 <a name="id2543358"></a><h2>DESCRIPTION</h2>
35 <p><span><strong class="command">Nslookup</strong></span>
36 is a program to query Internet domain name servers. <span><strong class="command">Nslookup</strong></span>
37 has two modes: interactive and non-interactive. Interactive mode allows
38 the user to query name servers for information about various hosts and
39 domains or to print a list of hosts in a domain. Non-interactive mode
41 used to print just the name and requested information for a host or
45 <div class="refsect1" lang="en">
46 <a name="id2543374"></a><h2>ARGUMENTS</h2>
48 Interactive mode is entered in the following cases:
50 <div class="orderedlist"><ol type="a">
52 when no arguments are given (the default name server will be used)
55 when the first argument is a hyphen (-) and the second argument is
56 the host name or Internet address of a name server.
62 Non-interactive mode is used when the name or Internet address of the
63 host to be looked up is given as the first argument. The optional second
64 argument specifies the host name or address of a name server.
67 Options can also be specified on the command line if they precede the
68 arguments and are prefixed with a hyphen. For example, to
69 change the default query type to host information, and the initial
70 timeout to 10 seconds, type:
73 <pre class="programlisting">
74 nslookup -query=hinfo -timeout=10
80 <div class="refsect1" lang="en">
81 <a name="id2543418"></a><h2>INTERACTIVE COMMANDS</h2>
82 <div class="variablelist"><dl>
83 <dt><span class="term"><code class="constant">host</code> [<span class="optional">server</span>]</span></dt>
86 Look up information for host using the current default server or
87 using server, if specified. If host is an Internet address and
88 the query type is A or PTR, the name of the host is returned.
89 If host is a name and does not have a trailing period, the
90 search list is used to qualify the name.
93 To look up a host not in the current domain, append a period to
97 <dt><span class="term"><code class="constant">server</code> <em class="replaceable"><code>domain</code></em></span></dt>
99 <dt><span class="term"><code class="constant">lserver</code> <em class="replaceable"><code>domain</code></em></span></dt>
101 Change the default server to <em class="replaceable"><code>domain</code></em>; <code class="constant">lserver</code> uses the initial
102 server to look up information about <em class="replaceable"><code>domain</code></em>, while <code class="constant">server</code> uses
103 the current default server. If an authoritative answer can't be
104 found, the names of servers that might have the answer are
107 <dt><span class="term"><code class="constant">root</code></span></dt>
111 <dt><span class="term"><code class="constant">finger</code></span></dt>
115 <dt><span class="term"><code class="constant">ls</code></span></dt>
119 <dt><span class="term"><code class="constant">view</code></span></dt>
123 <dt><span class="term"><code class="constant">help</code></span></dt>
127 <dt><span class="term"><code class="constant">?</code></span></dt>
131 <dt><span class="term"><code class="constant">exit</code></span></dt>
135 <dt><span class="term"><code class="constant">set</code>
136 <em class="replaceable"><code>keyword[<span class="optional">=value</span>]</code></em></span></dt>
139 This command is used to change state information that affects
140 the lookups. Valid keywords are:
142 <div class="variablelist"><dl>
143 <dt><span class="term"><code class="constant">all</code></span></dt>
145 Prints the current values of the frequently used
146 options to <span><strong class="command">set</strong></span>.
147 Information about the current default
148 server and host is also printed.
150 <dt><span class="term"><code class="constant">class=</code><em class="replaceable"><code>value</code></em></span></dt>
153 Change the query class to one of:
155 <div class="variablelist"><dl>
156 <dt><span class="term"><code class="constant">IN</code></span></dt>
160 <dt><span class="term"><code class="constant">CH</code></span></dt>
164 <dt><span class="term"><code class="constant">HS</code></span></dt>
168 <dt><span class="term"><code class="constant">ANY</code></span></dt>
174 The class specifies the protocol group of the information.
178 (Default = IN; abbreviation = cl)
181 <dt><span class="term"><code class="constant">
182 <em class="replaceable"><code>[<span class="optional">no</span>]</code></em>debug</code></span></dt>
185 Turn on or off the display of the full response packet and
186 any intermediate response packets when searching.
189 (Default = nodebug; abbreviation = [<span class="optional">no</span>]deb)
192 <dt><span class="term"><code class="constant">
193 <em class="replaceable"><code>[<span class="optional">no</span>]</code></em>d2</code></span></dt>
196 Turn debugging mode on or off. This displays more about
197 what nslookup is doing.
203 <dt><span class="term"><code class="constant">domain=</code><em class="replaceable"><code>name</code></em></span></dt>
205 Sets the search list to <em class="replaceable"><code>name</code></em>.
207 <dt><span class="term"><code class="constant">
208 <em class="replaceable"><code>[<span class="optional">no</span>]</code></em>search</code></span></dt>
211 If the lookup request contains at least one period but
212 doesn't end with a trailing period, append the domain
213 names in the domain search list to the request until an
220 <dt><span class="term"><code class="constant">port=</code><em class="replaceable"><code>value</code></em></span></dt>
223 Change the default TCP/UDP name server port to <em class="replaceable"><code>value</code></em>.
226 (Default = 53; abbreviation = po)
229 <dt><span class="term"><code class="constant">querytype=</code><em class="replaceable"><code>value</code></em></span></dt>
231 <dt><span class="term"><code class="constant">type=</code><em class="replaceable"><code>value</code></em></span></dt>
234 Change the type of the information query.
237 (Default = A; abbreviations = q, ty)
240 <dt><span class="term"><code class="constant">
241 <em class="replaceable"><code>[<span class="optional">no</span>]</code></em>recurse</code></span></dt>
244 Tell the name server to query other servers if it does not
249 (Default = recurse; abbreviation = [no]rec)
252 <dt><span class="term"><code class="constant">retry=</code><em class="replaceable"><code>number</code></em></span></dt>
254 Set the number of retries to number.
256 <dt><span class="term"><code class="constant">timeout=</code><em class="replaceable"><code>number</code></em></span></dt>
258 Change the initial timeout interval for waiting for a
259 reply to number seconds.
261 <dt><span class="term"><code class="constant">
262 <em class="replaceable"><code>[<span class="optional">no</span>]</code></em>vc</code></span></dt>
265 Always use a virtual circuit when sending requests to the
272 <dt><span class="term"><code class="constant">
273 <em class="replaceable"><code>[<span class="optional">no</span>]</code></em>fail</code></span></dt>
276 Try the next nameserver if a nameserver responds with
277 SERVFAIL or a referral (nofail) or terminate query
278 (fail) on such a response.
290 <div class="refsect1" lang="en">
291 <a name="id2546284"></a><h2>FILES</h2>
292 <p><code class="filename">/etc/resolv.conf</code>
295 <div class="refsect1" lang="en">
296 <a name="id2546296"></a><h2>SEE ALSO</h2>
297 <p><span class="citerefentry"><span class="refentrytitle">dig</span>(1)</span>,
298 <span class="citerefentry"><span class="refentrytitle">host</span>(1)</span>,
299 <span class="citerefentry"><span class="refentrytitle">named</span>(8)</span>.
302 <div class="refsect1" lang="en">
303 <a name="id2546330"></a><h2>Author</h2>