23 Oct 1998
nmblookup - NetBIOS over TCP/IP client used to lookup NetBIOS names
nmblookup [-M] [-R] [-S] [-r] [-A] [-h] [-B broadcast address] [-U unicast address] [-d debuglevel] [-s smb config file] [-i NetBIOS scope] [-T] name
This program is part of the Samba suite.
nmblookup is used to query NetBIOS names and map them to IP
addresses in a network using NetBIOS over TCP/IP queries. The options
allow the name queries to be directed at a particular IP broadcast area
or to a particular machine. All queries are done over UDP.
- Searches for a master browser by looking up the
NetBIOS name name with a type of 0x1d. If name
"-" then it does a lookup on the special name
- Set the recursion desired bit in the packet to do a
recursive lookup. This is used when sending a name query to a machine
running a WINS server and the user wishes to query the names in the
WINS server. If this bit is unset the normal (broadcast responding)
NetBIOS processing code on a machine is used instead. See rfc1001,
rfc1002 for details.
- Once the name query has returned an IP address then do a
node status query as well. A node status query returns the NetBIOS names
registered by a host.
- Try and bind to UDP port 137 to send and receive UDP
datagrams. The reason for this option is a bug in Windows 95 where it
ignores the source port of the requesting packet and only replies to
UDP port 137. Unfortunately, on most UNIX systems root privilage is
needed to bind to this port, and in addition, if the
nmbd daemon is running on this machine it also
binds to this port.
- Interpret <name> as an IP Address and do a node status
query on this address.
- Print a help (usage) message.
- -B broadcast address
- Send the query to the given broadcast
address. Without this option the default behavior of nmblookup is to
send the query to the broadcast address of the network
interfaces as either auto-detected or defined in the
interfaces parameter of the
smb.conf (5) file.
- -U unicast address
- Do a unicast query to the specified
address or host
"unicast address". This option (along with the
-R option) is needed to query a WINS server.
- -d debuglevel
- debuglevel is an integer from 0 to 10.
The default value if this parameter is not specified is zero.
The higher this value, the more detail will be logged about the
activities of nmblookup. At level 0, only critical errors and
serious warnings will be logged.
Levels above 1 will generate considerable amounts of log data, and
should only be used when investigating a problem. Levels above 3 are
designed for use only by developers and generate HUGE amounts of
data, most of which is extremely cryptic.
Note that specifying this parameter here will override the log
level parameter in the smb.conf
- -s smb.conf
- This parameter specifies the pathname to the
Samba configuration file, smb.conf.
This file controls all aspects of
the Samba setup on the machine.
- -i scope
- This specifies a NetBIOS scope that nmblookup will use
to communicate with when generating NetBIOS names. For details on the
use of NetBIOS scopes, see rfc1001.txt and rfc1002.txt. NetBIOS scopes
are very rarely used, only set this parameter if you are the
system administrator in charge of all the NetBIOS systems you
- This causes any IP addresses found in the lookup to be
looked up via a reverse DNS lookup into a DNS name, and printed out
"IP address NetBIOS name" pair that is the normal
- This is the NetBIOS name being queried. Depending upon
the previous options this may be a NetBIOS name or IP address. If a
NetBIOS name then the different name types may be specified by
#<type> to the name. This name may also be
which will return all registered names within a broadcast area.
nmblookup can be used to query a WINS server (in the same way
nslookup is used to query DNS servers). To query a WINS server,
nmblookup must be called like this:
nmblookup -U server -R 'name'
For example, running :
nmblookup -U samba.org -R IRIX#1B'
would query the WINS server samba.org for the domain master
browser (1B name type) for the IRIX workgroup.
This man page is correct for version 2.0 of the Samba suite.
samba (7), nmbd (8),
The original Samba software and related utilities were created by
Andrew Tridgell email@example.com. Samba is now developed
by the Samba Team as an Open Source project similar to the way the
Linux kernel is developed.
The original Samba man pages were written by Karl Auer. The man page
sources were converted to YODL format (another excellent piece of Open
Source software, available at
and updated for the Samba2.0 release by Jeremy Allison.
See samba (7) to find out how to get a full
list of contributors and details on how to submit bug reports,