|Developer(s)||Internet Systems Consortium, Andrew Cherenson, IBM, Microsoft, Lucas Suggs|
|Operating system||Unix, Unix-like, OS/2, Microsoft Windows, ReactOS|
|License||Microsoft Windows, IBM OS/2: Proprietary commercial software|
ReactOS: GNU General Public License
nslookup is a network administration command-line tool available in many computer operating systems for querying the Domain Name System (DNS) to obtain domain name or IP address mapping, or other DNS records. The name "nslookup" means "name server lookup".
nslookup was a member of the BIND name server software. Early[when?] in the development of BIND 9, the Internet Systems Consortium planned to deprecate nslookup in favor of host and dig. This decision was reversed in 2004 with the release of BIND 9.3 and nslookup has been fully supported since then.
The command does not use the operating system's local Domain Name System resolver library to perform its queries, and thus may behave differently from dig, which does. Additionally, vendor-provided versions may include output of other sources of name information, such as host files, and Network Information Service. Some behaviors of nslookup may be modified by the contents of resolv.conf.
nslookup operates in interactive or non-interactive mode. When used interactively by invoking it without arguments or when the first argument is - (minus sign) and the second argument is a hostname or Internet address of a name server, the user issues parameter configurations or requests when presented with the nslookup prompt (
>). When no arguments are given, then the command queries the default server. The - (minus sign) invokes subcommands which are specified on the command line and should precede nslookup commands. In non-interactive mode, i.e. when the first argument is a name or Internet address of the host being searched, parameters and the query are specified as command line arguments in the invocation of the program. The non interactive mode searches the information for a specified host using the default name server.
- "BIND 9.3.0 is now available". Isc.org. 2004-09-23. Retrieved 2015-01-13.
- "DNS and BIND, Fourth Edition: Chapter 12. nslookup and dig". O'Reilly. Retrieved 20 July 2010.
- "nslookup(1) - Linux man page". linux.die.net.
- "reactos/reactos". GitHub.
- "pSeries and AIX Information Center". Publib.boulder.ibm.com. Archived from the original on 2013-01-03. Retrieved 2012-09-05.
- Barrett, Daniel J. (2012). Macintosh Terminal Pocket Guide: Take Command of Your Mac. O'Reilly. ISBN 978-1449328986.
- Stanek, William R. (2008). Windows Command-Line Administrator's Pocket Consultant, 2nd Edition. Microsoft Press. ISBN 978-0735622623.
|Wikiversity has learning resources about Nslookup|
|Wikibooks has a book on the topic of: Guide to Windows Commands|