NSLOOKUP(1) BIND9 NSLOOKUP(1)
nslookup - query Internet name servers interactively
nslookup [-option] [name | -] [server]
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
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:
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
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.
Exits the program.
This command is used to change state information that affects the
lookups. Valid keywords are:
Prints the current values of the frequently used options to
set. Information about the current default server and host
is also printed.
Change the query class to one of:
the Internet class
the Chaos class
the Hesiod class
The class specifies the protocol group of the
(Default = IN; abbreviation = cl)
Turn on or off the display of the full response packet and
any intermediate response packets when searching.
(Default = nodebug; abbreviation = [no]deb)
Turn debugging mode on or off. This displays more about
what nslookup is doing.
(Default = nod2)
Sets the search list to name.
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
(Default = search)
Change the default TCP/UDP name server port to value.
(Default = 53; abbreviation = po)
Change the type of the information query.
(Default = A; abbreviations = q, ty)
Tell the name server to query other servers if it does not
have the information.
(Default = recurse; abbreviation = [no]rec)
Set the number of retries to number.
Change the initial timeout interval for waiting for a reply
to number seconds.
Always use a virtual circuit when sending requests to the
(Default = novc)
[no]failTry the next nameserver if a nameserver responds
with SERVFAIL or
a referral (nofail) or terminate query (fail) on
such a response.
(Default = nofail)
dig(1), host(1), named(8).
Copyright (C) 2004-2007 Internet Systems Consortium, Inc. ("ISC")
BIND9 Jun 30, 2000 NSLOOKUP(1)