In the opening chapter, we mentioned that in order for a Windows workgroup or domain to extend into multiple subnets, one machine would have to take the role of the
domain master browser. The domain master browser propagates browse lists across each of the subnets in the workgroup. This works because each local master browser periodically synchronizes its browse list with the domain master browser. During this synchronization, the local master browser passes on any server that the domain master browser does not have in its browse list, and vice versa. In a perfect world, each local master browser would eventually have the browse list for the entire domain.
Unlike the local master browser, there is no election to determine which machine assumes the role of the domain master browser. Instead, the administrator has to set it manually. By Microsoft design, however, the domain master browser and the primary domain controller (PDC) both register a resource type of <1B>, so the roles - and the machines - are inseparable.
If you have a Windows NT server on the network acting as a PDC, we recommend that you do not use Samba to become the domain master browser. The reverse is true as well: if Samba is taking on the responsibilities of a PDC, we recommend making it the domain master browser as well. Although it is possible to split the roles with Samba, this is not a good idea. Using two different machines to serve as the PDC and the domain master browser can cause random errors to occur on a Windows workgroup.
Samba can assume the role of a domain master browser for all subnets in the workgroup with the following option:
domain master = yes
You can verify that a Samba machine is in fact the domain master browser by checking the
nmbd log file:
nmbd/nmbd_become_dmb.c:become_domain_master_stage2(118)
*****
Samba name server HYDRA is now a domain master browser for
workgroup SIMPLE on subnet 192.168.220.100
*****
Or you can use the
nmblookup command that comes with the Samba distribution to query for a unique <1B> resource type in the workgroup:
#
nmblookup SIMPLE#1B
Sending queries to 192.168.220.255
192.168.220.100 SIMPLE<1b>
