1192886Sedwin.. Copyright (C) Internet Systems Consortium, Inc. ("ISC") 2192886Sedwin.. 364499Swollman.. SPDX-License-Identifier: MPL-2.0 4273719Sedwin.. 52742Swollman.. This Source Code Form is subject to the terms of the Mozilla Public 6273719Sedwin.. License, v. 2.0. If a copy of the MPL was not distributed with this 7273719Sedwin.. file, you can obtain one at https://mozilla.org/MPL/2.0/. 82742Swollman.. 9274563Sedwin.. See the COPYRIGHT file distributed with this work for additional 10274563Sedwin.. information regarding copyright ownership. 11274563Sedwin 12158421Swollman.. highlight: console 13158421Swollman 14274563Sedwin.. iscman:: nslookup 152742Swollman.. program:: nslookup 1686222Swollman.. _man_nslookup: 1720094Swollman 1820094Swollmannslookup - query Internet name servers interactively 1920094Swollman---------------------------------------------------- 20274563Sedwin 21274563SedwinSynopsis 2220094Swollman~~~~~~~~ 23274563Sedwin 24274563Sedwin:program:`nslookup` [-option] [name | -] [server] 25274563Sedwin 2620094SwollmanDescription 2719878Swollman~~~~~~~~~~~ 2819878Swollman 2919878Swollman:program:`nslookup` is a program to query Internet domain name servers. 3019878Swollman:program:`nslookup` has two modes: interactive and non-interactive. Interactive 3119878Swollmanmode allows the user to query name servers for information about various 3219878Swollmanhosts and domains or to print a list of hosts in a domain. 33270817SpluknetNon-interactive mode prints just the name and requested 3419878Swollmaninformation for a host or domain. 3558787Sru 3658787SruArguments 3758787Sru~~~~~~~~~ 38270817Spluknet 3958787SruInteractive mode is entered in the following cases: 4058787Sru 41270817Splukneta. when no arguments are given (the default name server is used); 42270817Spluknet 43270817Spluknetb. when the first argument is a hyphen (-) and the second argument is 4458787Sru the host name or Internet address of a name server. 4558787Sru 4658787SruNon-interactive mode is used when the name or Internet address of the 4758787Sruhost to be looked up is given as the first argument. The optional second 4858787Sruargument specifies the host name or address of a name server. 4958787Sru 50270817SpluknetOptions can also be specified on the command line if they precede the 5158787Sruarguments and are prefixed with a hyphen. For example, to change the 5258787Srudefault query type to host information, with an initial timeout of 10 532742Swollmanseconds, type: 542742Swollman 552742Swollman:: 562742Swollman 572742Swollman nslookup -query=hinfo -timeout=10 582742Swollman 592742SwollmanThe ``-version`` option causes :program:`nslookup` to print the version number 6019878Swollmanand immediately exit. 612742Swollman 622742SwollmanInteractive Commands 632742Swollman~~~~~~~~~~~~~~~~~~~~ 64270817Spluknet 652742Swollman``host [server]`` 662742Swollman This command looks up information for :iscman:`host` using the current default server or 67149514Swollman using ``server``, if specified. If :iscman:`host` is an Internet address and the 6821217Swollman query type is A or PTR, the name of the host is returned. If :iscman:`host` is 699908Swollman a name and does not have a trailing period (``.``), the search list is used 709908Swollman to qualify the name. 712742Swollman 7219878Swollman To look up a host not in the current domain, append a period to the 7319878Swollman name. 7419878Swollman 7519878Swollman``server domain`` | ``lserver domain`` 7619878Swollman These commands change the default server to ``domain``; ``lserver`` uses the initial 7719878Swollman server to look up information about ``domain``, while ``server`` uses the 7819878Swollman current default server. If an authoritative answer cannot be found, 7919878Swollman the names of servers that might have the answer are returned. 8019878Swollman 8119878Swollman``root`` 8219878Swollman This command is not implemented. 8319878Swollman 8419878Swollman``finger`` 8519878Swollman This command is not implemented. 8619878Swollman 8719878Swollman``ls`` 8893799Swollman This command is not implemented. 8958787Sru 9058787Sru``view`` 9119878Swollman This command is not implemented. 9219878Swollman 9319878Swollman``help`` 949908Swollman This command is not implemented. 95149514Swollman 969908Swollman``?`` 979908Swollman This command is not implemented. 98270817Spluknet 9921217Swollman``exit`` 10019878Swollman This command exits the program. 10119878Swollman 1029908Swollman``set keyword[=value]`` 103149514Swollman This command is used to change state information that affects the 1049908Swollman lookups. Valid keywords are: 1059908Swollman 1069908Swollman ``all`` 1079908Swollman This keyword prints the current values of the frequently used options to 10858787Sru ``set``. Information about the current default server and host is 10958787Sru also printed. 11058787Sru 11164499Swollman ``class=value`` 11264499Swollman This keyword changes the query class to one of: 113175034Sedwin 114175034Sedwin ``IN`` 115175034Sedwin the Internet class 116175034Sedwin 117175034Sedwin ``CH`` 11858787Sru the Chaos class 11958787Sru 120270817Spluknet ``HS`` 12158787Sru the Hesiod class 12258787Sru 12358787Sru ``ANY`` 124270817Spluknet wildcard 12564499Swollman 126270817Spluknet The class specifies the protocol group of the information. The default 12764499Swollman is ``IN``; the abbreviation for this keyword is ``cl``. 12864499Swollman 12986222Swollman ``nodebug`` 13086222Swollman This keyword turns on or off the display of the full response packet, and any 13186222Swollman intermediate response packets, when searching. The default for this keyword is 13286222Swollman ``nodebug``; the abbreviation for this keyword is ``[no]deb``. 13386222Swollman 13486222Swollman ``nod2`` 13586222Swollman This keyword turns debugging mode on or off. This displays more about what 13686222Swollman nslookup is doing. The default is ``nod2``. 13786222Swollman 13886222Swollman ``domain=name`` 13986222Swollman This keyword sets the search list to ``name``. 14086222Swollman 14186222Swollman ``nosearch`` 14286222Swollman If the lookup request contains at least one period, but does not end 14386222Swollman with a trailing period, this keyword appends the domain names in the domain 14486222Swollman search list to the request until an answer is received. The default is ``search``. 14586222Swollman 14686222Swollman ``port=value`` 14786222Swollman This keyword changes the default TCP/UDP name server port to ``value`` from 14886222Swollman its default, port 53. The abbreviation for this keyword is ``po``. 14986222Swollman 15086222Swollman ``querytype=value`` | ``type=value`` 15186222Swollman This keyword changes the type of the information query to ``value``. The 152175034Sedwin defaults are A and then AAAA; the abbreviations for these keywords are 153175034Sedwin ``q`` and ``ty``. 154175034Sedwin 155175034Sedwin Please note that it is only possible to specify one query type. Only the default 156175034Sedwin behavior looks up both when an alternative is not specified. 157175034Sedwin 158175034Sedwin ``norecurse`` 159270817Spluknet This keyword tells the name server to query other servers if it does not have 160175034Sedwin the information. The default is ``recurse``; the abbreviation for this 161270817Spluknet keyword is ``[no]rec``. 162175034Sedwin 163175034Sedwin ``ndots=number`` 164175034Sedwin This keyword sets the number of dots (label separators) in a domain that 165175034Sedwin disables searching. Absolute names always stop searching. 166175034Sedwin 167175034Sedwin ``retry=number`` 168175034Sedwin This keyword sets the number of retries to ``number``. 169175034Sedwin 170183066Sedwin ``timeout=number`` 171183066Sedwin This keyword changes the initial timeout interval to wait for a reply to 172183066Sedwin ``number``, in seconds. 173183066Sedwin 174183066Sedwin ``novc`` 175183066Sedwin This keyword indicates that a virtual circuit should always be used when sending requests to the server. 176183066Sedwin ``novc`` is the default. 177183066Sedwin 178183864Sedwin ``nofail`` 179183864Sedwin This keyword tries the next nameserver if a nameserver responds with SERVFAIL or 180183864Sedwin a referral (nofail), or terminates the query (fail) on such a response. The 181183864Sedwin default is ``nofail``. 182183864Sedwin 183183864SedwinReturn Values 184183864Sedwin~~~~~~~~~~~~~ 185183864Sedwin 186183864Sedwin:program:`nslookup` returns with an exit status of 1 if any query failed, and 0 187183864Sedwinotherwise. 188183864Sedwin 189183864SedwinIDN Support 190184406Sedwin~~~~~~~~~~~ 191273719Sedwin 192273719SedwinIf :program:`nslookup` has been built with IDN (internationalized domain name) 193184406Sedwinsupport, it can accept and display non-ASCII domain names. :program:`nslookup` 194184406Sedwinappropriately converts character encoding of a domain name before sending 195270817Splukneta request to a DNS server or displaying a reply from the server. 196270817SpluknetTo turn off IDN support, define the ``IDN_DISABLE`` 197270817Spluknetenvironment variable. IDN support is disabled if the variable is set 198270817Spluknetwhen :program:`nslookup` runs, or when the standard output is not a tty. 199184406Sedwin 200184406SedwinFiles 201273719Sedwin~~~~~ 202273719Sedwin 203273719Sedwin``/etc/resolv.conf`` 204184406Sedwin 205184406SedwinSee Also 206198515Sedwin~~~~~~~~ 207198515Sedwin 208198515Sedwin:iscman:`dig(1) <dig>`, :iscman:`host(1) <host>`, :iscman:`named(8) <named>`. 209273719Sedwin