nslookup

NSLOOKUP(1)                          BIND9                         NSLOOKUP(1)

NAME
       nslookup - query Internet name servers interactively

SYNOPSIS
       nslookup [-option] [name | -] [server]

DESCRIPTION
       Nslookup is a program to query Internet domain name servers.  Nslookup
       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.

ARGUMENTS
       Interactive mode is entered in the following cases:

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

        2. when the first argument is a hyphen (-) and the second argument is
           the host name or Internet address of a name server.

       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.

       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:

           nslookup -query=hinfo  -timeout=10

       The -version option causes nslookup to print the version number and
       immediately exits.

INTERACTIVE COMMANDS
       host [server]
           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.

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

       server domain

       lserver domain
           Change the default server to domain; lserver uses the initial
           server to look up information about domain, while server uses the
           current default server. If an authoritative answer can't be found,
           the names of servers that might have the answer are returned.

       root
           not implemented

       finger
           not implemented

       ls
           not implemented

       view
           not implemented

       help
           not implemented

       ?
           not implemented

       exit
           Exits the program.

       set keyword[=value]
           This command is used to change state information that affects the
           lookups. Valid keywords are:

           all
               Prints the current values of the frequently used options to
               set. Information about the current default server and host is
               also printed.

           class=value
               Change the query class to one of:

               IN
                   the Internet class

               CH
                   the Chaos class

               HS
                   the Hesiod class

               ANY
                   wildcard

               The class specifies the protocol group of the information.

               (Default = IN; abbreviation = cl)

           [no]debug
               Turn on or off the display of the full response packet and any
               intermediate response packets when searching.

               (Default = nodebug; abbreviation = [no]deb)

           [no]d2
               Turn debugging mode on or off. This displays more about what
               nslookup is doing.

               (Default = nod2)

           domain=name
               Sets the search list to name.

           [no]search
               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.

               (Default = search)

           port=value
               Change the default TCP/UDP name server port to value.

               (Default = 53; abbreviation = po)

           querytype=value

           type=value
               Change the type of the information query.

               (Default = A and then AAAA; abbreviations = q, ty)

               Note: It is only possible to specify one query type, only the
               default behavior looks up both when an alternative is not
               specified.

           [no]recurse
               Tell the name server to query other servers if it does not have
               the information.

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

           ndots=number
               Set the number of dots (label separators) in a domain that will
               disable searching. Absolute names always stop searching.

           retry=number
               Set the number of retries to number.

           timeout=number
               Change the initial timeout interval for waiting for a reply to
               number seconds.

           [no]vc
               Always use a virtual circuit when sending requests to the
               server.

               (Default = novc)

           [no]fail
               Try the next nameserver if a nameserver responds with SERVFAIL
               or a referral (nofail) or terminate query (fail) on such a
               response.

               (Default = nofail)

RETURN VALUES
       nslookup returns with an exit status of 1 if any query failed, and 0
       otherwise.

IDN SUPPORT
       If nslookup has been built with IDN (internationalized domain name)
       support, it can accept and display non-ASCII domain names.  nslookup
       appropriately converts character encoding of domain name before sending
       a request to DNS server or displaying a reply from the server. If you'd
       like to turn off the IDN support for some reason, define the
       IDN_DISABLE environment variable. The IDN support is disabled if the
       variable is set when nslookup runs or when the standard output is not a
       tty.

FILES
       /etc/resolv.conf

SEE ALSO
       dig(1), host(1), named(8).

AUTHOR
       Internet Systems Consortium, Inc.

COPYRIGHT
       Copyright (C) 2004-2007, 2010, 2013-2020 Internet Systems Consortium,
       Inc. ("ISC")

ISC                               2014-01-24                       NSLOOKUP(1)