path: root/usr.sbin/bind/bin/dig/nslookup.8

.\"	$OpenBSD: nslookup.8,v 1.3 2003/02/19 11:49:42 jakob Exp $
.\"
.\" ++Copyright++ 1985, 1989
.\" -
.\" Copyright (c) 1985, 1989
.\"    The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\" 	This product includes software developed by the University of
.\" 	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\" -
.\" Portions Copyright (c) 1993 by Digital Equipment Corporation.
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies, and that
.\" the name of Digital Equipment Corporation not be used in advertising or
.\" publicity pertaining to distribution of the document or software without
.\" specific, written prior permission.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
.\" WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
.\" CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
.\" DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
.\" PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
.\" ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
.\" SOFTWARE.
.\" -
.\" --Copyright--
.\"
.\"	@(#)nslookup.8	5.3 (Berkeley) 6/24/90
.\"
.Dd June 24, 1990
.Dt NSLOOKUP 8
.Os BSD 4
.Sh NAME
.Nm nslookup
.Nd query Internet name servers interactively
.Sh SYNOPSIS
.Nm nslookup
.Op Fl option Ar ...
.Op Ar host-to-find | Fl Op Ar server
.Sh DESCRIPTION
.Ic Nslookup
is a program to query Internet domain name servers.
.Ic 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.
.Sh ARGUMENTS
Interactive mode is entered in the following cases:
.Bl -tag -width "a)  "
.It a)
when no arguments are given (the default name server will be used),
.It b)
when the first argument is a hyphen (-) and the second argument
is the host name or Internet address of a name server.
.El
.Pp
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.
.Pp
The options listed under the
.Dq Li set
command below can be specified in
the
.Pa .nslookuprc
file in the user's home directory if they are listed
one per line.
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:
.Bd -literal -offset indent
	nslookup -query=hinfo  -timeout=10
.Ed
.Sh INTERACTIVE COMMANDS
Commands may be interrupted at any time by typing a control-C.
To exit, type a control-D
.Pq Dv EOF
or type
.Li exit .
The command line length must be less than 256 characters.
To treat a built-in command as a host name,
precede it with an escape character
.Pq .&\\ .
.Sy N.B.:  An unrecognized command will be interpreted as a host name.
.Bl -tag -width "lserver"
.It Ar host Op Ar server
Look up information for
.Ar host
using the current default server or using
.Ar server ,
if specified.
If
.Ar host
is an Internet address and the query type is
.Dv A
or
.Dv PTR ,
the name of the host is returned.
If
.Ar host
is a name and does not have a trailing period, the default
domain name is appended to the name.
(This behavior depends on the state of the
.Ic set
options
.Ic domain , srchlist , defname ,
and
.Ic search . )
.Pp
To look up a host not in the current domain, append a period to
the name.
.It Ic server Ar domain
.It Ic lserver Ar domain
Change the default server to
.Ar domain ;
.Ic lserver
uses the initial server to look up information about
.Ar domain ,
while
.Ic 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.
.It Ic exit
Exits the program.
.It Xo
.Ic set
.Ar keyword Ns Op = Ns Ar value
.Xc
This command is used to change state information that affects the lookups.
Valid keywords are:
.Bl -tag -width "class=v"
.It Ic all
Prints the current values of the frequently used options to
.Ic set .
Information about the  current default server and host is also printed.
.It Ic class Ns = Ns Ar value
Change the query class to one of:
.Bl -tag -width "HESIOD  "
.It Dv IN
the Internet class
.It Dv CHAOS
the Chaos class
.It Dv HESIOD
the MIT Athena Hesiod class
.It Dv ANY
wildcard (any of the above)
.El
.Pp
The class specifies the protocol group of the information.
.Pp
(Default =
.Dv IN ;
abbreviation =
.Ic cl )
.It Xo
.Oo Ic no Oc Ns Ic debug
.Xc
Turn debugging mode on.
A lot more information is printed about the
packet sent to the server and the resulting answer.
.Pp
(Default =
.Ic nodebug ;
abbreviation =
.Oo Ic no Oc Ns Ic deb )
.It Xo
.Oo Ic no Oc Ns Ic d2
.Xc
Turn exhaustive debugging mode on.
Essentially all fields of every packet are printed.
.Pp
(Default =
.Ic nod2 )
.It Ic domain Ns = Ns Ar name
Change the default domain name to
.Ar name .
The default domain name is appended to a lookup request depending on the
state of the
.Ic defname
and
.Ic search
options.
The domain search list contains the parents of the default domain if it has
at least two components in its name.
For example, if the default domain
is CC.Berkeley.EDU, the search list is CC.Berkeley.EDU and Berkeley.EDU.
Use the
.Dq Ic set srchlist
command to specify a different list.
Use the
.Dq Ic set all
command to display the list.
.Pp
(Default = value from
.Xr hostname 1 ,
.Pa /etc/resolv.conf ,
or
.Ev LOCALDOMAIN ;
abbreviation =
.Ic do )
.It Xo
.Sm off
.Ic srchlist No =
.Ar name1 No /
.Ar name2 No /
.Ar ...
.Sm on
.Xc
Change the default domain name to
.Ar name1
and the domain search list
to
.Ar name1 , name2 ,
etc.
A maximum of 6 names separated by slashes (/)
can be specified.
For example,
.Bd -literal -offset indent
set srchlist=lcs.MIT.EDU/ai.MIT.EDU/MIT.EDU
.Ed
.Pp
sets the domain to lcs.MIT.EDU and the search list to the three names.
This command overrides the
default domain name and search list of the
.Dq Ic set domain
command.
Use the
.Dq Ic set all
command to display the list.
.Pp
(Default = value based on
.Xr hostname 1 ,
.Pa /etc/resolv.conf ,
or
.Ev LOCALDOMAIN ;
abbreviation =
.Ic srchl )
.It Xo
.Oo Ic no Oc Ns Ic defname
.Xc
If set, append the default domain name to a single-component lookup request
(i.e., one that does not contain a period).
.Pp
(Default =
.Ic defname ;
abbreviation =
.Oo Ic no Oc Ns Ic defname )
.It Xo
.Oo Ic no Oc Ns Ic search
.Xc
If the lookup request contains at least one period but
.Em doesn't
end with a trailing period, append the domain names in the domain search list
to the request until an answer is received.
.Pp
(Default =
.Ic search ;
abbreviation =
.Oo Ic no Oc Ns Ic sea )
.It Ic port Ns = Ns Ar value
Change the default TCP/UDP name server port to
.Ar value .
.Pp
(Default = 53;
abbreviation =
.Ic \&po )
.It Ic querytype Ns = Ns Ar value
.It Ic type Ns = Ns Ar value
Change the type of information query to one of:
.Bl -tag -width "HINFO   "
.It Dv A
the host's Internet address.
.It Dv CNAME
the canonical name for an alias.
.It Dv HINFO
the host CPU and operating system type.
.It Dv MINFO
the mailbox or mail list information.
.It Dv MX
the mail exchanger.
.It Dv NS
the name server for the named zone.
.It Dv PTR
the host name if the query is an Internet address;
otherwise, the pointer to other information.
.It Dv SOA
the domain's
.Dq start-of-authority
information.
.It Dv TXT
the text information.
.It Dv UINFO
the user information.
.It Dv WKS
the supported well-known services.
.El
.Pp
Other types
.Dv ( ANY , AXFR , MB ,
.Dv MD , MF , NULL )
are described in the RFC-1035 document.
.Pp
(Default =
.Dv A ;
abbreviations =
.Ic q , ty )
.It Xo
.Oo Ic no Oc Ns Ic recurse
.Xc
Tell the name server to query other servers if it does not have the
information.
.Pp
(Default =
.Ic recurse ;
abbreviation =
.Oo Ic no Oc Ns Ic rec )
.It Ic retry Ns = Ns Ar number
Set the number of retries to
.Ar number .
When a reply to a request is not received within a certain
amount of time (changed with
.Dq Ic set timeout ) ,
the timeout period is doubled and the request is resent.
The retry value controls how many times a request is resent before giving up.
.Pp
(Default = 4, abbreviation =
.Ic ret )
.It Ic root Ns = Ns Ar host
Change the name of the root server to
.Ar host .
This affects the
.Dq Ic root
command.
.Pp
(Default =
.Ic ns.internic.net. ;
abbreviation =
.Ic ro )
.It Ic timeout Ns = Ns Ar number
Change the initial timeout interval for waiting for a reply to
.Ar number
seconds.
Each retry doubles the timeout period.
.Pp
(Default = 5 seconds; abbreviation =
.Ic ti )
.It Xo
.Oo Ic no Oc Ns Ic vc
.Xc
Always use a virtual circuit when sending requests to the server.
.Pp
(Default =
.Ic novc ;
abbreviation =
.Oo Ic no Oc Ns Ic v )
.El
.El
.Sh DIAGNOSTICS
If the lookup request was not successful, an error message is printed.
Possible errors are:
.Bl -tag -width "Timed"
.It Li Timed out
The server did not respond to a request after a certain amount of
time (changed with
.Dq Ic set timeout Ns = Ns Ar value )
and a certain number of retries (changed with
.Do
.Ic set retry Ns = Ns Ar value
.Dc ) .
.It Li \&No response from server
No name server is running on the server machine.
.It Li \&No records
The server does not have resource records of the current query type for the
host, although the host name is valid.
The query type is specified with the
.Dq Ic set querytype
command.
.It Li Non-existent domain
The host or domain name does not exist.
.It Li Connection refused
.It Li Network is unreachable
The connection to the name or finger server could not be made
at the current time.
This error commonly occurs with
.Ic ls
and
.Ic finger
requests.
.It Li Server failure
The name server found an internal inconsistency in its database
and could not return a valid answer.
.It Li Refused
The name server refused to service the request.
.It Li Format error
The name server found that the request packet was not in the proper format.
It may indicate an error in
.Nm nslookup .
.El
.Sh FILES
.Bl -tag -width "/etc/resolv.confXXX" -compact
.It Pa /etc/resolv.conf
initial domain name and name server addresses
.El
.Sh SEE ALSO
.Xr dig 1 ,
.Xr named 8 ,
.Xr resolver 3 ,
.Xr resolver 5 ;
RFC-1034,
.Dq Domain Names - Concepts and Facilities ;
RFC-1035,
.Dq Domain Names - Implementation and Specification .
.Sh AUTHOR
Andrew Cherenson