Integration with WINS

Windows Internet Name Service (WINS) provides dynamic name resolution for the NetBIOS namespace. Before Windows 2000, WINS was required on all clients and servers. The Windows NT 4.0 DNS server provided a feature called WINS lookup. With WINS lookup , you can direct DNS to query WINS for name resolution, so that DNS clients can look up the names and IP addresses of WINS clients. Windows 2000 still supports WINS lookup, although for DHCP clients, you can use dynamic update instead, provided that the DHCP server is running Windows 2000.

For more information about dynamic update, see "Dynamic Update and Secure Dynamic Update" earlier in this chapter. For more information about WINS, see "Windows Internet Name Service" in this book.

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WINS is not required in a purely Windows 2000 environment.

To use WINS lookup integration, you add two special resource records — the WINS and WINS-R resource records — to your forward and reverse lookup zones, respectively. When a DNS server that is authoritative for that zone is queried for a name that it does not find in the authoritative zone, and the zone is configured to use WINS resolution, the DNS server queries the WINS server. If the name is registered with WINS, the WINS server returns the associated record to the DNS server.

Reverse lookups work slightly differently. When an authoritative DNS server is queried for a nonexistent PTR record, and the authoritative zone contains the WINS-R record, the DNS server uses a NetBIOS node adapter status lookup.

Finally, the DNS server returns the name or IP address in response to the original DNS request. Thus, DNS clients do not need to know whether a client is registered with WINS or DNS, nor do they need to query the WINS server.

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For fault tolerance, you can specify multiple WINS servers. The server that is running the Windows 2000 Server DNS service tries to locate the name by searching the WINS servers in the order specified by the list.