nmblookup Man page

Resume Wikipedia de NetBIOS

NetBIOS est une architecture réseau codéveloppée par IBM et Sytek (en) au début des années 1980. NetBIOS est utilisé principalement par Microsoft. Ce n’est pas un protocole réseau, mais un système de nommage et une interface logicielle qui permet d’établir des sessions entre différents ordinateurs d’un réseau.
NetBIOS a connu plusieurs implémentations :
NBF (NetBIOS Frames Protocol, connu à tort sous le nom NetBEUI)
Les deux premières ont disparu de nos jours.
Les noms NetBIOS sont appelés à disparaître en faveur des noms DNS. De plus, le partage de fichiers avec le protocole SMB peut à présent se passer de NetBIOS et fonctionner directement par-dessus TCP/IP.



nmblookup – NetBIOS over TCP/IP client used to lookup NetBIOS names


nmblookup [-M|–master-browser] [-R|–recursion] [-S|–status] [-r|–root-port] [-A|–lookup-by-ip] [-B|–broadcast ] [-U|–unicast ] [-d ] [-s ] [-i ] [-T|–translate] [-f|–flags] {name}


This tool is part of the samba(7) 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 with a
type of 0x1d. If
name is “-” then it does a lookup on the special name
__MSBROWSE__. Please note that in order to use the name “-“, you
need to make sure “-” isn’t parsed as an argument, e.g. use :
nmblookup -M — -.

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 privilege is needed
to bind to this port, and in addition, if the nmbd(8) 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

-n|–netbiosname This option allows you to override the NetBIOS name that Samba uses
for itself. This is identical to setting the netbios name parameter
in the smb.conf file. However, a command line setting will take
precedence over settings in smb.conf.

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
communicate with.

Set the SMB domain of the username. This overrides the default
domain which is the domain defined in smb.conf. If the domain
specified is the same as the servers NetBIOS name, it causes the
client to log on using the servers local SAM (as opposed to the
Domain SAM).

-O|–socket-options socket options
TCP socket options to set on the client socket. See the socket
options parameter in the smb.conf manual page for the list of valid

Print a summary of command line options.

Display brief usage message.

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.

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.

level is an integer from 0 to 10. The default value if this
parameter is not specified is 0.

The higher this value, the more detail will be logged to the log
files about the activities of the server. At level 0, only critical
errors and serious warnings will be logged. Level 1 is a reasonable
level for day-to-day running – it generates a small amount of
information about operations carried out.

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 log data, most of which is extremely cryptic.

Note that specifying this parameter here will override the log
level parameter in the smb.conf file.

Prints the program version number.

The file specified contains the configuration details required by
the server. The information in this file includes server-specific
information such as what printcap file to use, as well as
descriptions of all the services that the server is to provide. See
smb.conf for more information. The default configuration file name
is determined at compile time.

Base directory name for log/debug files. The extension “.progname”
will be appended (e.g. log.smbclient, log.smbd, etc…). The log
file is never removed by the client.

Set the smb.conf(5) option “” to value “” from the
command line. This overrides compiled-in defaults and options read
from the configuration file.

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 before

IP address …. NetBIOS name

pair that is the normal output.

Show which flags apply to the name that has been looked up.
Possible answers are zero or more of: Response, Authoritative,
Truncated, Recursion_Desired, Recursion_Available, Broadcast.

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 appending
‘#‘ 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 3 of the Samba suite.


nmbd(8), samba(7), and smb.conf(5).


The original Samba software and related utilities were created by
Andrew Tridgell. 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 ftp://ftp.icce.rug.nl/pub/unix/) and
updated for the Samba 2.0 release by Jeremy Allison. The conversion to
DocBook for Samba 2.2 was done by Gerald Carter. The conversion to
DocBook XML 4.2 for Samba 3.0 was done by Alexander Bokovoy.

Samba 4.3 09/23/2016 NMBLOOKUP(1)