<refentry xmlns="http://docbook.org/ns/docbook" version="5.0">

<info>

<date>2014-01-24</date>

</info>

<refentryinfo>

<corpname>ISC</corpname>

<corpauthor>Internet Systems Consortium, Inc.</corpauthor>

</refentryinfo>

<refmeta>

<refentrytitle>nslookup</refentrytitle>

<manvolnum>1</manvolnum>

<refmiscinfo>BIND9</refmiscinfo>

</refmeta>

<refnamediv>

<refname>nslookup</refname>

<refpurpose>query Internet name servers interactively</refpurpose>

</refnamediv>

<docinfo>

<copyright>

<year>2004</year>

<year>2005</year>

<year>2006</year>

<year>2007</year>

<year>2010</year>

<year>2013</year>

<year>2014</year>

<year>2015</year>

<year>2016</year>

<holder>Internet Systems Consortium, Inc. ("ISC")</holder>

</copyright>

</docinfo>

<refsynopsisdiv>

<cmdsynopsis sepchar=" ">

<command>nslookup</command>

<arg choice="opt" rep="norepeat"><option>-option</option></arg>

<arg choice="opt" rep="norepeat">name | -</arg>

<arg choice="opt" rep="norepeat">server</arg>

</cmdsynopsis>

</refsynopsisdiv>

<refsection><info><title>DESCRIPTION</title></info>

<para><command>Nslookup</command>

is a program to query Internet domain name servers. <command>Nslookup</command>

has two modes: interactive and non-interactive. Interactive mode allows

the user to query name servers for information about various hosts and

domains or to print a list of hosts in a domain. Non-interactive mode

is

used to print just the name and requested information for a host or

domain.

</para>

</refsection>

<refsection><info><title>ARGUMENTS</title></info>

<para>

Interactive mode is entered in the following cases:

<orderedlist numeration="loweralpha" inheritnum="ignore" continuation="restarts">

<listitem>

<para>

when no arguments are given (the default name server will be used)

</para>

</listitem>

<listitem>

<para>

when the first argument is a hyphen (-) and the second argument is

the host name or Internet address of a name server.

</para>

</listitem>

</orderedlist>

</para>

<para>

Non-interactive mode is used when the name or Internet address of the

host to be looked up is given as the first argument. The optional second

argument specifies the host name or address of a name server.

</para>

<para>

Options can also be specified on the command line if they precede the

arguments and are prefixed with a hyphen. For example, to

change the default query type to host information, and the initial

timeout to 10 seconds, type:

<!-- <informalexample> produces bad nroff. -->

<programlisting>

nslookup -query=hinfo -timeout=10

</programlisting>

<!-- </informalexample> -->

</para>

<para>

The <option>-version</option> option causes

<command>nslookup</command> to print the version

number and immediately exits.

</para>

</refsection>

<refsection><info><title>INTERACTIVE COMMANDS</title></info>

<variablelist>

<varlistentry>

<term><constant>host</constant> <optional>server</optional></term>

<listitem>

<para>

Look up information for host using the current default server or

using server, if specified. If host is an Internet address and

the query type is A or PTR, the name of the host is returned.

If host is a name and does not have a trailing period, the

search list is used to qualify the name.

</para>

<para>

To look up a host not in the current domain, append a period to

the name.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>server</constant> <replaceable class="parameter">domain</replaceable></term>

<listitem>

<para/>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>lserver</constant> <replaceable class="parameter">domain</replaceable></term>

<listitem>

<para>

Change the default server to <replaceable>domain</replaceable>; <constant>lserver</constant> uses the initial

server to look up information about <replaceable>domain</replaceable>, while <constant>server</constant> uses

the current default server. If an authoritative answer can't be

found, the names of servers that might have the answer are

returned.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>root</constant></term>

<listitem>

<para>

not implemented

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>finger</constant></term>

<listitem>

<para>

not implemented

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>ls</constant></term>

<listitem>

<para>

not implemented

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>view</constant></term>

<listitem>

<para>

not implemented

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>help</constant></term>

<listitem>

<para>

not implemented

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>?</constant></term>

<listitem>

<para>

not implemented

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>exit</constant></term>

<listitem>

<para>

Exits the program.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>set</constant>

<replaceable>keyword<optional>=value</optional></replaceable></term>

<listitem>

<para>

This command is used to change state information that affects

the lookups. Valid keywords are:

<variablelist>

<varlistentry>

<term><constant>all</constant></term>

<listitem>

<para>

Prints the current values of the frequently used

options to <command>set</command>.

Information about the current default

server and host is also printed.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>class=</constant><replaceable>value</replaceable></term>

<listitem>

<para>

Change the query class to one of:

<variablelist>

<varlistentry>

<term><constant>IN</constant></term>

<listitem>

<para>

the Internet class

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>CH</constant></term>

<listitem>

<para>

the Chaos class

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>HS</constant></term>

<listitem>

<para>

the Hesiod class

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>ANY</constant></term>

<listitem>

<para>

wildcard

</para>

</listitem>

</varlistentry>

</variablelist>

The class specifies the protocol group of the information.

</para>

<para>

(Default = IN; abbreviation = cl)

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>

<replaceable><optional>no</optional></replaceable>debug</constant></term>

<listitem>

<para>

Turn on or off the display of the full response packet and

any intermediate response packets when searching.

</para>

<para>

(Default = nodebug; abbreviation = <optional>no</optional>deb)

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>

<replaceable><optional>no</optional></replaceable>d2</constant></term>

<listitem>

<para>

Turn debugging mode on or off. This displays more about

what nslookup is doing.

</para>

<para>

(Default = nod2)

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>domain=</constant><replaceable>name</replaceable></term>

<listitem>

<para>

Sets the search list to <replaceable>name</replaceable>.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>

<replaceable><optional>no</optional></replaceable>search</constant></term>

<listitem>

<para>

If the lookup request contains at least one period but

doesn't end with a trailing period, append the domain

names in the domain search list to the request until an

answer is received.

</para>

<para>

(Default = search)

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>port=</constant><replaceable>value</replaceable></term>

<listitem>

<para>

Change the default TCP/UDP name server port to <replaceable>value</replaceable>.

</para>

<para>

(Default = 53; abbreviation = po)

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>querytype=</constant><replaceable>value</replaceable></term>

<listitem>

<para/>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>type=</constant><replaceable>value</replaceable></term>

<listitem>

<para>

Change the type of the information query.

</para>

<para>

(Default = A; abbreviations = q, ty)

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>

<replaceable><optional>no</optional></replaceable>recurse</constant></term>

<listitem>

<para>

Tell the name server to query other servers if it does not

have the

information.

</para>

<para>

(Default = recurse; abbreviation = [no]rec)

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>ndots=</constant><replaceable>number</replaceable></term>

<listitem>

<para>

Set the number of dots (label separators) in a domain

that will disable searching. Absolute names always

stop searching.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>retry=</constant><replaceable>number</replaceable></term>

<listitem>

<para>

Set the number of retries to number.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>timeout=</constant><replaceable>number</replaceable></term>

<listitem>

<para>

Change the initial timeout interval for waiting for a

reply to number seconds.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>

<replaceable><optional>no</optional></replaceable>vc</constant></term>

<listitem>

<para>

Always use a virtual circuit when sending requests to the

server.

</para>

<para>

(Default = novc)

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>

<replaceable><optional>no</optional></replaceable>fail</constant></term>

<listitem>

<para>

Try the next nameserver if a nameserver responds with

SERVFAIL or a referral (nofail) or terminate query

(fail) on such a response.

</para>

<para>

(Default = nofail)

</para>

</listitem>

</varlistentry>

</variablelist>

</para>

</listitem>

</varlistentry>

</variablelist>

</refsection>

<refsection><info><title>RETURN VALUES</title></info>

<para>

<command>nslookup</command> returns with an exit status of 1

if any query failed, and 0 otherwise.

</para>

</refsection>

<refsection><info><title>FILES</title></info>

<para><filename>/etc/resolv.conf</filename>

</para>

</refsection>

<refsection><info><title>SEE ALSO</title></info>

<para><citerefentry>

<refentrytitle>dig</refentrytitle><manvolnum>1</manvolnum>

</citerefentry>,

<citerefentry>

<refentrytitle>host</refentrytitle><manvolnum>1</manvolnum>

</citerefentry>,

<citerefentry>

<refentrytitle>named</refentrytitle><manvolnum>8</manvolnum>

</citerefentry>.

</para>

</refsection>

</refentry>