NSLOOKUP(1) BIND 9 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:
a. when no arguments are given (the default name server will be used)
b. 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 sec-
ond 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 im-
mediately 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.
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 re-
turned.
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 informa-
tion.
(Default = IN; abbreviation = cl)
nodebug
Turn on or off the display of the full response packet
and any intermediate response packets when searching.
(Default = nodebug; abbreviation = [no]deb)
nod2 Turn debugging mode on or off. This displays more about
what nslookup is doing.
(Default = nod2)
domain=name
Sets the search list to name.
nosearch
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 and then AAAA; abbreviations = q, ty)
Note: It is only possible to specify one query type, only
the default
behavior looks up both when an alternative is not
specified.
norecurse
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 re-
ply to number seconds.
novc Always use a virtual circuit when sending requests to the
server.
(Default = novc)
nofail Try the next nameserver if a nameserver responds with
SERVFAIL or a referral (nofail) or terminate query (fail)
on such a response.
(Default = nofail)
RETURN VALUES
nslookup returns with an exit status of 1 if any query failed, and 0
otherwise.
IDN SUPPORT
If nslookup has been built with IDN (internationalized domain name)
support, it can accept and display non-ASCII domain names. nslookup ap-
propriately converts character encoding of domain name before sending a
request to DNS server or displaying a reply from the server. If you'd
like to turn off the IDN support for some reason, define the IDN_DIS-
ABLE environment variable. The IDN support is disabled if the variable
is set when nslookup runs or when the standard output is not a tty.
FILES
/etc/resolv.conf
SEE ALSO
dig(1), host(1), named(8).
AUTHOR
Internet Systems Consortium
COPYRIGHT
2020, Internet Systems Consortium
9.16.8-Debian 2020-10-13 NSLOOKUP(1)