Manual dla nslookup


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:


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

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.

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

(Default = IN; abbreviation = cl)

Turn debugging mode on. A lot more information is printed
about the packet sent to the server and the resulting

(Default = nodebug; abbreviation = [no]deb)

[no]d2 Turn debugging mode on. A lot more information is printed
about the packet sent to the server and the resulting

(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 received.

(Default = search)

Change the default TCP/UDP name server port to value.

(Default = 53; abbreviation = po)


Change the top 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.

[no]vc Always use a virtual circuit when sending requests to the

(Default = novc)


dig(1), host(1), named(8).

Andrew Cherenson

BIND9 Jun 30, 2000 NSLOOKUP(1)