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 domain.
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.
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; 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.
(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)
nslookup returns with an exit status of 1 if any query
failed, and 0 otherwise.
Internet Systems Consortium, Inc.
Copyright © 2004-2007, 2010, 2013-2019 Internet Systems
Consortium, Inc. ("ISC")