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.
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.
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:
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.
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.
port=value
Change the default TCP/UDP name server port to value.
(Default = 53; abbreviation = po)
type=value
Change the type of the information query.
(Default = A; abbreviations = q, ty)
[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.
[no]fail
Try the next nameserver if a nameserver responds with SERVFAIL or a referral (nofail)
or terminate query (fail) on such a response.
RETURN VALUES
nslookup returns with an exit status of 1 if any query failed, and 0 otherwise.
SEE ALSO
dig(1), host(1), named(8).
AUTHOR
Internet Systems Consortium, Inc.
COPYRIGHT
Copyright © 2004-2007, 2010, 2013-2017 Internet Systems Consortium, Inc. ("ISC")
ISC 2014-01-24 NSLOOKUP(1)
