14.6. Samba Network Browsing
Network browsing is a concept that enables Windows and Samba servers to appear in the Windows Network Neighborhood. Inside the Network Neighborhood, icons are represented as servers and if opened, the server's shares and printers that are available are displayed.
Network browsing capabilities require NetBIOS over TCP/IP. NetBIOS-based networking uses broadcast (UDP) messaging to accomplish browse list management. Without NetBIOS and WINS as the primary method for TCP/IP hostname resolution, other methods such as static files (/etc/hosts) or DNS, must be used.
A domain master browser collates the browse lists from local master browsers on all subnets so that browsing can occur between workgroups and subnets. Also, the domain master browser should preferably be the local master browser for its own subnet.
14.6.1. Workgroup Browsing
For each workgroup, there must be one and only one domain master browser. You can have one local master browser per subnet without a domain master browser, but this results in isolated workgroups unable to see each other. To resolve NetBIOS names in cross-subnet workgroups, WINS is required.
 | Note |
|---|---|
The Domain Master Browser can be the same machine as the WINS server. |
There can only be one domain master browser per workgroup name. Here is an example of the smb.conf file in which the Samba server is a domain master browser:
[global] domain master = Yes local master = Yes preferred master = Yes os level = 35 |
Next is an example of the smb.conf file in which the Samba server is a local master browser:
[global] domain master = no local master = Yes preferred master = Yes os level = 35 |
The os level directive operates as a priority system for master browsers in a subnet. Setting different values ensures master browsers do not conflict with each other for authority.
 | Tip |
|---|---|
Lowering the os level directive results in Samba conflicting with other master browsers on the same subnet. The higher the value, the higher the priority. The highest a Windows server can operate at is 32. This is a good way of tuning multiple local master browsers. |
There are instances when a Windows NT machine on the subnet could be the local master browser. The following is an example smb.conf configuration in which the Samba server is not serving in any browsing capacity:
[global] domain master = no local master = no preferred master = no os level = 0 |
 | Warning |
|---|---|
Having multiple local master browsers result in each server competing for browsing election requests. Make sure there is only one local master browser per subnet. |
14.6.2. Domain Browsing
By default, a Windows NT PDC for a domain is also the domain master browser for that domain. A Samba server must be set up as a domain master server in this type of situation. Network browsing may fail if the Samba server is running WINS along with other domain controllers in operation.
For subnets that do not include the Windows NT PDC, a Samba server can be implemented as a local master browser. Configuring the smb.conf for a local master browser (or no browsing at all) in a domain controller environment is the same as workgroup configuration.
14.6.3. WINS (Windows Internetworking Name Server)
Either a Samba server or a Windows NT server can function as a WINS server. When a WINS server is used with NetBIOS enabled, UDP unicasts can be routed which allows name resolution across networks. Without a WINS server, the UDP broadcast is limited to the local subnet and therefore cannot be routed to other subnets, workgroups, or domains. If WINS replication is necessary, do not use Samba as your primary WINS server, as Samba does not currently support WINS replication.
In a mixed NT/2000/2003 server and Samba environment, it is recommended that you use the Microsoft WINS capabilities. In a Samba-only environment, it is recommended that you use only one Samba server for WINS.
The following is an example of the smb.conf file in which the Samba server is serving as a WINS server:
[global] wins support = Yes |
| Tip |
|---|---|
All servers (including Samba) should connect to a WINS server to resolve NetBIOS names. Without WINS, browsing only occurs on the local subnet. Furthermore, even if a domain-wide list is somehow obtained, hosts are not resolvable for the client without WINS. |