WINS Database

When a client is turned off, it releases its name, but there is a WINS extinction interval that allows the record to remain for some period of time in case the client is turned on again (as in the case of a reboot). The extinction interval reservs the record for some period so other clients cannot use it until the interval expires. WINS files are in SystemRoot\System32\Wins. A file names WINS.MDB is used to store a WINS database which can be backed up and repaired. The WINS service will back up the database every three hours (by default) to the configured backup path. Version numbers can be used to backup minor changes. The only way to replace a new copy with an older copy is to delete the old database copy first. The easy way to restore a database is to force replication from a WINS partner with a good copy of the database.

The database contains the following records:

• Renewal interval - Equivalent to the DHCP lease interval, it is the amount of time for the client to re-register the NetBIOS name before it is released.
• Extinction interval - The time a releast record exists before being tombstoned.
• Extinction timeout - The time a tombstoned record exists before being erased.
• Verification interval - The time an active record exists before being verified with the name owner.

WINS Proxy Agent

A WINS proxy agent can be configured to act as a relay for non-WINS clients. The WINS proxy agent can intercept client broadcast requests, forward them to a WINS server and return the response. It may also reply with the response without contacting the WINS server if the required information is in its cache. One WINS proxy is used on each subnet that has non-WINS clients. This means that machines that are not using WINS (Even Windows machines such as those without TCP/IP) can use a proxy agent to let them find resources on other subnets. There should be a maximum of two proxy agents per subnet. The agent must be a Windows based client, not a server. When NetBIOSs names are registered, both the proxy agent and the WINS server checks the name. The proxy agent is configured at the following registry location:

Hkey_Local_Machine\System\CurrentControlSet\Services\NetBT\Parameters

Set the EnableProxy parameter to REG_DWORD value of 1 and restart the computer.