17.1 Using WINS in DSfW Environment

Beginning with OES 11 SP2, you can configure a DSfW server as a WINS server. Configuring a DSfW server as a WINS server helps to prevent having two workstations with the same name in a domain. If a workstation client is configured to use a WINS server, before joining a domain, the administrator is alerted if a workstation with the same name already exists in the domain.

Duplicate workstation names in a domain can lead to several problems. If your domain has duplicate workstations, users might experience slow logins to the domain. Logins might take several minutes instead of seconds. You will also require substantial recovery effort to bring back configuration to a unique workstation name across a domain.

Configuring a DSfW server as a WINS server also changes the NetBIOS join functionality. Without WINS server, a NetBIOS join will not work if there is no domain controller in the subnet. However, with WINS support, the join will work if the workstation's WINS configuration points to a domain controller that is configured as a WINS server.

17.1.1 Planning for WINS Support

Use the following guidelines to configure a WINS server:

  • You can configure only one DSfW domain controller as a WINS server in a domain. All the workstations in the domain must be configured to use this domain controller as the WINS server.

  • Microsoft or any other OES server should not be configured as a WINS or a WINS proxy server for the workstations in the domain.

  • DSfW server cannot be configured as a WINS proxy server.

  • DSfW WINS server helps in detecting workstations with duplicate names. Any other WINS functionality is not supported.

  • Ensure that the client workstation's firewall for UDP port 137 is disabled.

  • Ensure that the gateways between DSfW server and Windows clients have the UDP port 137 disabled for messages originating from server to workstation.

  • If you have a significant number of workstations that are part of the domain, then DHCP service can be used for configuring these workstations as WINS clients.

17.1.2 Configuring WINS Server and Client

Configuring WINS Server

You can configure WINS server by selecting the Configure this machine to be a WINS server check box while installing and configuring DSfW using YaST. For information, see Configure this machine to be a WINS server:.

Configuring WINS Client

  1. On a Windows system, click Start and point to Control Panel.

  2. Click Network and Dial-up Connections > Local Area Connections > Properties.

  3. Select the Internet Protocol (TCP/IP) Properties entry in the list and then click Properties> Advanced > WINS Address tab.

  4. Select the Disable NetBIOS over TCP/IP option.

  5. Click Add.

  6. Specify the IP address or the domain name of the WINS server.

17.1.3 Migrating WINS Server

This section describes how to migrate a DSfW WINS server from one domain controller to another.

Before you migrate WINS, ensure that you stop the nmb service on the server where WINS is configured and take a backup of the wins.dat and wins.tdb files (/var/lib/samba). Follow the steps given below to migrate WINS:

  1. Verify if WINS is configured on the server by running the following command:

    /opt/novell/xad/share/dcinit/configure_dsfw_wins.pl --isconfigured-upgrade 
  2. Unconfigure WINS on the source server.

  3. Verify if WINS is configured on the server by running the following command:

    /opt/novell/xad/share/dcinit/configure_dsfw_wins.pl --isconfigured-upgrade 
  4. Configure WINS on the target server.

  5. Stop the nmb process in the target server.

    rcnmb stop
  6. Copy the wins.dat and wins.tdb files (/var/lib/samba) from the source server to the target server.

  7. Start the nmb process.

    rcnmb start
  8. Reconfigure WINS clients to point to the target server. For more information on configuring WINS clients, see Configuring WINS Client.

17.1.4 Caveats

  • If you have workstations joined to the domain prior to the WINS configuration, you must ensure that you configure those workstations as WINS clients after the WINS server configuration and reboot those clients. This will add workstation names to the WINS database and ensure that their duplicate names are detected.

  • You can configure only one DSfW domain controller as a WINS server in a domain. Therefore, if the WINS service goes down, any workstation join with a duplicate name will not be reported. Also, if a workstation is down, a duplicate workstation join will not be reported. To identify workstations with duplicate names during such scenarios, follow the steps below:

  1. Run the following command:

    /opt/novell/xad/share/dcinit/checkdupws.pl --current 
  2. Ensure that you have unique workstation names.

  3. Run the following command:

    /opt/novell/xad/share/dcinit/checkdupws.pl --clear-cache 

    This will clear the duplicate workstation name cache and display the list of duplicate workstation names that are cleared.

    You can also schedule this script to be run after a specified interval. To schedule the script, run the following command:

    /opt/novell/xad/share/dcinit/checkdupws.pl --schedule=<interval in hours> 

    This schedules the script to be run periodically in the specified interval. The script is run with the --clear-cache option in the scheduled interval. The /var/opt/novell/xad/log/wins_duplicate_check.log will list the duplicate workstation names.