nmbd - NetBIOS name server to provide NetBIOS over IP naming services
nmbd [ -D ] [ -a ] [ -i ] [ -o ] [ -P ] [ -h ] [ -V ] [ -d
<debug level> ] [ -H <lmhosts file> ] [ -l <log directory> ] [ -n
<primary netbios name> ] [ -p <port number> ] [ -s <configuration
This program is part of the Samba suite.
nmbd is a server that understands and can reply to NetBIOS over IP name
service requests, like those produced by SMB/CIFS clients such as Win-
dows 95/98/ME, Windows NT, Windows 2000, and LanManager clients. It
also participates in the browsing protocols which make up the Windows
"Network Neighborhood" view.
SMB/CIFS clients, when they start up, may wish to locate an SMB/CIFS
server. That is, they wish to know what IP number a specified host is
Amongst other services, nmbd will listen for such requests, and if its
own NetBIOS name is specified it will respond with the IP number of the
host it is running on. Its "own NetBIOS name" is by default the primary
DNS name of the host it is running on, but this can be overridden with
the -n option (see OPTIONS below). Thus nmbd will reply to broadcast
queries for its own name(s). Additional names for nmbd to respond on
can be set via parameters in the smb.conf(5) configuration file.
nmbd can also be used as a WINS (Windows Internet Name Server) server.
What this basically means is that it will act as a WINS database
server, creating a database from name registration requests that it
receives and replying to queries from clients for these names.
In addition, nmbd can act as a WINS proxy, relaying broadcast queries
from clients that do not understand how to talk the WINS protocol to a
-D If specified, this parameter causes nmbd to operate as a daemon.
That is, it detaches itself and runs in the background, fielding
requests on the appropriate port. By default, nmbd will operate
as a daemon if launched from a command shell. nmbd can also be
operated from the inetd meta-daemon, although this is not recom-
-a If this parameter is specified, each new connection will append
log messages to the log file. This is the default.
-i If this parameter is specified it causes the server to run
"interactively", not as a daemon, even if the server is executed
on the command line of a shell. Setting this parameter negates
the implicit deamon mode when run from the command line.
-o If this parameter is specified, the log files will be overwrit-
ten when opened. By default, smbd will append entries to the log
-h Prints the help information (usage) for nmbd.
NetBIOS lmhosts file. The lmhosts file is a list of NetBIOS
names to IP addresses that is loaded by the nmbd server and used
via the name resolution mechanism name resolve order described
in smb.conf(5) to resolve any NetBIOS name queries needed by
the server. Note that the contents of this file are NOT used by
nmbd to answer any name queries. Adding a line to this file
affects name NetBIOS resolution from this host ONLY.
The default path to this file is compiled into Samba as part of
the build process. Common defaults are
/usr/local/samba/lib/lmhosts, /usr/samba/lib/lmhosts or
/etc/lmhosts. See the lmhosts(5) man page for details on the
contents of this file.
-V Prints the version number for nmbd.
-d <debug level>
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 to the log
files about the activities of the server. At level 0, only crit-
ical 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.
-l <log directory>
The -l parameter specifies a directory into which the "log.nmbd"
log file will be created for operational data from the running
nmbd server. The default log directory is compiled into Samba as
part of the build process. Common defaults are
/usr/local/samba/var/log.nmb, /usr/samba/var/log.nmb or
/var/log/log.nmb. Beware: If the directory specified does not
exist, nmbd will log to the default debug log location defined
at compile time.
-n <primary NetBIOS name>
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.
-p <UDP port number>
UDP port number is a positive integer value. This option
changes the default UDP port number (normally 137) that nmbd
responds to name queries on. Don't use this option unless you
are an expert, in which case you won't need help!
-s <configuration file>
The default configuration file name is set at build time, typi-
cally as /usr/local/samba/lib/smb.conf, but this may be changed
when Samba is autoconfigured.
The file specified contains the configuration details required
by the server. See smb.conf(5) for more information.
If the server is to be run by the inetd meta-daemon, this file
must contain suitable startup information for the meta-daemon.
See the UNIX_INSTALL.html document for details.
or whatever initialization script your system uses).
If running the server as a daemon at startup, this file will
need to contain an appropriate startup sequence for the server.
See the UNIX_INSTALL.html document for details.
If running the server via the meta-daemon inetd, this file must
contain a mapping of service name (e.g., netbios-ssn) to service
port (e.g., 139) and protocol type (e.g., tcp). See the
UNIX_INSTALL.html document for details.
This is the default location of the smb.conf server configura-
tion file. Other common places that systems install this file
are /usr/samba/lib/smb.conf and /etc/smb.conf.
When run as a WINS server (see the wins support parameter in the
smb.conf(5) man page), nmbd will store the WINS database in the
file wins.dat in the var/locks directory configured under wher-
ever Samba was configured to install itself.
If nmbd is acting as a browse master (see the local master
parameter in the smb.conf(5) man page, nmbd will store the
browsing database in the file browse.dat in the var/locks direc-
tory configured under wherever Samba was configured to install
To shut down an nmbd process it is recommended that SIGKILL (-9) NOT be
used, except as a last resort, as this may leave the name database in
an inconsistent state. The correct way to terminate nmbd is to send it
a SIGTERM (-15) signal and wait for it to die on its own.
nmbd will accept SIGHUP, which will cause it to dump out its namelists
into the file namelist.debug in the /usr/local/samba/var/locks direc-
tory (or the var/locks directory configured under wherever Samba was
configured to install itself). This will also cause nmbd to dump out
its server database in the log.nmb file.
The debug log level of nmbd may be raised or lowered using smbcon-
(SIGUSR[1|2] signals are no longer used in Samba 2.2). This is to
allow transient problems to be diagnosed, whilst still running at a
normally low log level.
One of the common causes of difficulty when installing Samba and SWAT
is the existsnece of some type of firewall or port filtering software
on the Samba server. Make sure that the appropriate ports outlined in
this man page are available on the server and are not currently being
blocked by some type of security software such as iptables or "port
sentry". For more troubleshooting information, refer to the additional
documentation included in the Samba distribution.
This man page is correct for version 2.2 of the Samba suite.
inetd(8), smbd(8) smb.conf(5)
and the Internet RFC's rfc1001.txt, rfc1002.txt. In addition the CIFS
(formerly SMB) specification is available as a link from the Web page
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/
<URL: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
19 November 2002 NMBD(8)