samba-mirror/docs/textdocs/BROWSING.txt

BROWSING
========

Samba now fully supports browsing. The browsing is supported by nmbd
and is also controlled by options in the smb.conf file (see
smb.conf(5)).

Samba can act as a browse master for a workgroup, but currently cannot
act as a domain controller. The ability to be a domain controller will
be added in a later version.

To get browsing to work you need to run nmbd as usual, but will need
to use the "workgroup" option in smb.conf to control what workgroup
Samba becomes a part of.

The -G option is most useful for simple setups where Samba is browsable
in only one workgroup. In more complex cases the lmhosts file is
better.

Be very careful setting up your lmhosts file. An incorrectly setup
lmhosts file can have disasterous results for your net!

A simple lmhosts file might be:

# This is a simple lmhosts file
#
# This is a host alias. Anyone querying this name
# will get the specified IP
192.0.2.17 SMBDATA
#
# first put ourselves in workgroup MYGROUP using
# our own net address
0.0.0.0 MYGROUP 255.255.255.0 G

Note in the above that I overrode what workgroup Samba is in using the
G flag. Also note that the 0.0.0.0 address is used, which will be
automatically replaced with the broadcast address for groups, and with
the local IP address for other entries.

Samba also has a useful option for a Samba server to offer itself for
browsing on another subnet.

This works by the lmhosts file specifying a broadcast address on the
other network to use to find a browse master for the workgroup.

For example if you wanted yourself to appear in the workgroup STAFF on
the network which has a broadcast of 192.0.3.255 then this entry would
do the trick:

# put ourselves in the STAFF workgroup on the other subnet
192.0.3.255 STAFF 255.255.255.0 G

Notice the G at the end! It is very important you include this as this
entry without the G could cause a broadcast storm! 

If something doesn't work then hopefully the log.nmb file will
help you track down the problem. Try a debug level of 2 or 3 for
finding problems.

Note that if it doesn't work for you, then you should still be able to
type the server name as \\SERVER in filemanager then hit enter and
filemanager should display the list of available shares.

Some people find browsing fails because they don't have the global
"guest account" set to a valid account. Remember that the IPC$
connection that lists the shares is done as guest, and thus you must
have a valid guest account.

Also, a lot of people are getting bitten by the problem of too many
parameters on the command line of nmbd in inetd.conf. This trick is to
not use spaces between the option and the parameter (eg: -d2 instead
of -d 2), and to not use the -B and -N options. New versions of nmbd
are now far more likely to correctly find your broadcast and network
addess, so in most cases these aren't needed.

The other big problem people have is that their broadcast address,
netmask or IP address is wrong (specified with the -B, -N and -I
options to nmbd). 

FORCING SAMBA TO BE THE MASTER
==============================

Who becomes the "master browser" is determined by an election process
using broadcasts. Each election packet contains a number of parameters
which determine what precedence (bias) a host should have in the
election. By default Samba uses a very low precedence and thus loses
elections to just about anyone else.

If you want Samba to win elections then just set the "os level" global
option in smb.conf to a higher number. It defaults to 0. Using 33
would make it win all elections over every other system (except other
samba systems!)

A "os level" of 2 would make it beat WfWg and Win95, but not NTAS. A
NTAS domain controller uses level 32.

The maximum os level is 255

MAKING SAMBA THE DOMAIN MASTER
==============================

The domain master is responsible for collating the browse lists of
multiple subnets so that browsing can occur between subnets. You can
make samba act as the domain master by setting "domain master = yes"
in smb.conf. By default it will not be a domain master.

When samba is the domain master and the master browser it will listen
for master announcements from other subnets and then contact them to
synchronise browse lists.

If you want samba to be the domain master then I suggest you also set
the "os level" high enough to make sure it wins elections.

NOTIFYING THE DOMAIN CONTROLLER
===============================

If you have a domain controller for the domain which Samba is a part
of then you should add the line "domain controller = address" to
smb.conf. "address" can either be a name available via DNS or a IP
address or a broadcast address. If it is a broadcast address then
Samba will look for a domain controller on that network.

When Samba is the master browser it will regularly contact the domain
controller to synchronise browse lists.


NOTE ABOUT BROADCAST ADDRESSES
==============================

If your network uses a "0" based broadcast address (for example if it
ends in a 0) then you will strike problems. Windows for Workgroups
does not seem to support a 0's broadcast and you will probably find
that browsing and name lookups won't work.

You have a few options:

1) change to a 1's broadcast on your unix server. These often end in
.255 (check with your local network guru for details)

2) set the nmbd broadcast to a 1's based address on the command line using
the -B option. This only works if your network setup listens on both
0s and 1s based broadcasts. The -B option can only control what
address it sends to, not what it listens on.

MULTIPLE INTERFACES
===================

Samba now supports machines with multiple network interfaces. If you
have multiple interfaces then you will need to use the "interfaces"
option in smb.conf to configure them. See smb.conf(5) for details.