WINS Client Support

AS/U NetBIOS is WINS compliant. AS/U provides WINS client functionality as well as the ability to contact primary and secondary WINS servers. AS/U NetBIOS also contains features to enhance interoperability with Windows NT 4.0 clients. See the "Windows NT 4.0 Client Interoperability" section in this chapter for more details. With WINS client support, AS/U servers can use a Windows NT WINS server to perform NetBIOS name registration and name resolution. Name registration is how each networked computer acquires a unique name. When an AS/U server starts, it registers itself with the WINS server. Name resolution identifies the specific IP address linked to a computer name.

	NOTE: The AS/U server can not act as the WINS server. The database of WINS information is contained in a Windows NT server.

Previous versions of NetBIOS for AS/U registered and resolved names by sending UDP broadcasts over a computer subnet. This limited the NetBIOS name services to a single subnet. The method, also known as B-Node NetBIOS, is the default method used when WINS client support is not enabled.

When WINS client support is enabled, a WINS client first attempts to do name registration and name resolution by contacting a WINS server directly via a UDP unicast. If a WINS server is unavailable and/or doesn't respond, NetBIOS will revert to using its default method of using broadcasts to do name registration and name resolution. This method of first contacting the WINS server and then broadcasting if a WINS server is unavailable is known as H-Node NetBIOS.

When a secondary (or backup) WINS server is present, the WINS client performs name registration as follows: 1) try to contact primary WINS server (if configured), 2) if no response, try to contact the secondary WINS server (if configured), and 3) if no response, try broadcast.

When a secondary (or backup) WINS server is present, the WINS client performs name resolution as follows: 1) try to contact primary WINS server (if configured), 2) if no response or if failed, try to contact the secondary WINS server (if configured), and 3) if no response or if failed, try broadcast.

The secondary WINS server can only be configured if a primary WINS server is also configured.

The NetBIOS name cache can still be used to access the IP address of a computer. To add or delete names in the local NetBIOS name cache, use the nbutil utility. When WINS client support is enabled, name resolution is done in the following order:

The WINS server provides a distributed database for registering and querying dynamic computer name-to-IP address mapping in a routed network environment. With WINS client support, AS/U servers will operate more seamlessly in routed networks.

Windows NT 4.0 Client Interoperability

Two NetBIOS features provide interoperability with Windows NT 4.0 clients. AS/U NetBIOS allows Windows NT 4.0 clients to connect to AS/U servers as follows:

• by using non-fully qualified DNS names or,

• by IP address (for example: \\192.170.128.21\share).

Enabling WINS Client Support

Use the following steps to enable WINS client support:

1. After installing AS/U, stop the AS/U server and RFC-NetBIOS.

   1. net stop server (to stop AS/U Server)

   2. /opt/lmu/netbios/bin/nbutil -N stop (to stop NetBIOS)

2. Configure the IP address of the WINS server in the NetBIOS configuration file (/etc/opt/lmu/netbios/nbconfig) using /opt/lmu/netbios/bin/autoconfig. The syntax is as follows (refer to the next section for a list of autoconfig options):

   /opt/lmu/netbios/bin/autoconfig -w WINS Server IP Address

   	NOTE: Note: the IP address of the WINS server is not the IP address of the AS/U server.

   Example:

   /opt/lmu/netbios/bin/autoconfig -w 15.13.1.1

3. Restart NetBIOS and the AS/U Server

   1. /opt/lmu/netbios/bin/nbutil -N start (to start NetBIOS).

   2. net start server (to start AS/U Server)

4. Ensure all clients are configured for WINS. Clients supporting WINS are Windows NT clients, Windows 95, and Windows for Workgroups 3.11 with 32-bit TCP/IP. LAN Manager 2.2c clients cannot use WINS.

Disabling WINS Client Support

Use the following steps to disable WINS client support:

1. Stop the AS/U server and RFC-NetBIOS.

   net stop server (to stop the AS/U Server)

   /opt/lmu/netbios/bin/nbutil stop (to stop NetBIOS).

2. Remove the WINS server IP address in the NetBIOS configuration file (/etc/opt/lmu/netbios/nbconfig) using /opt/lmu/netbios/bin/autoconfig.

   Example: /opt/lmu/netbios/bin/autoconfig -w 0 [-s 0]

3. Restart NetBIOS and the AS/U Server.

   1. /opt/lmu/netbios/bin/nbutil -N start (to start NetBIOS).

   2. net start server (to start the AS/U Server)

Using the Autoconfig Utility

The /opt/lmu/netbios/bin/autoconfig utility saves existing configuration data in the NetBIOS nbconfig file. It only updates the data related to the option you specify. For example, if you specify autoconfig -w IP address, the utility adds information about the WINS server address to the previously saved data.

Following are the options for the autoconfig utility:

autoconfig [-l lan#][-u 1|0][-w WINS server IP address] [-s Secondary WINS server IP address][-i IP address] [-b Broadcast address][-m Subnet mask]

• -l lan# specify a LAN card to configure NetBIOS to. example: autoconfig -l lan0

• -u 1|0 configure UDP ports to single LAN card

• -w WINS server IP address specify a WINS Server IP Address example: autoconfig -w 15.13.2.3

• -s secondary WINS server IP address specify a secondary (backup) WINS Server IP Address example: autoconfig -s 15.13.2.4

• -i IP address specify an IP address that NetBIOS should bind to. example: autoconfig -i 15.13.2.5

• -b Broadcast address specify a broadcast Address example: autoconfig -v 15.13.255.255

• -m Subnet mask specify a subnet mask for NetBIOS to use. example: autoconfig -m 255.255.248.0

Usage Notes

The autoconfig -l option is normally used to configure NetBIOS. This option will configure NetBIOS with the IP address, broadcast address, and subnet mask configured for the lan interface specified. The autoconfig -i -b, -m and -u options are only needed in special circumstances when you need to override the default configuration information obtained from the lan interface with the -l option.