The Windows Internet Naming Service

The Windows Internet Naming Service (WINS) has a long and sordid history in Microsoft networks. In the beginning, Microsoft networks were primarily broadcast-based, using protocols such as NetBEUI to identify local computers. The problem with this type of name resolution was that it did not scale beyond multiple subnets, which were fast becoming the norm in modern networks. With the adoption of TCP/IP as an easily routable protocol, the need to translate NetBIOS computer names with IP addresses became a reality. This need gave rise to the development of WINS.

Legacy Microsoft NetBIOS Resolution

WINS is effectively a simple database of NetBIOS names and their corresponding IP addresses. Some additional information, such as domain name, server type, and so on, can be determined as well, from the 16th byte in a NetBIOS name stored in WINS.

WINS is considered legacy in the Microsoft world because NetBIOS resolution is being phased out in favor of the Domain Name System (DNS) form of name resolution. However, it is difficult to divorce WINS from modern networks because of the reliance on WINS by down-level (pre-Windows 2000) clients, legacy applications, and even some Microsoft services such as DFS that utilize NetBIOS resolution by default. Consequently, it is often necessary to keep using WINS in Windows networks, unless it can be definitively proven that it is no longer necessary.

WINS and DNS Integration

DNS can use the WINS database to provide for quasi-DNS resolution of WINS clients. This means that if a request is sent to a DNS server to resolve client1.companyabc.com, for example, it is possible for that DNS server to use the WINS database to resolve requests for any zones where the WINS forward lookup is configured. If Client1 does not exist in the DNS database but exists in the WINS database instead, the DNS server will return the IP address that it obtained from WINS and attach the companyabc.com suffix to the record, as illustrated in Figure 10.14.

Figure 10.14. WINS integration with DNS.

This functionality must be enabled on the DNS server because it is not configured by default. To enable WINS resolution on a DNS server, follow these steps:

1.	On a server running DNS, open the DNS MMC snap-in (Start, Administrative Tools, DNS).
2.	Navigate to DNS\<Servername>\Forward Lookup Zones.
3.	Right-click the zone in question and choose Properties.
4.	Choose the WINS tab.
5.	Check the Use WINS Forward Lookup box.
6.	Enter the IP address of the WINS server(s) and click OK to save the changes, as illustrated in Figure 10.15. Figure 10.15. Configuring WINS resolution in DNS.

For more information on DNS configuration, refer to Chapter 9.

Changes in Windows Server 2003 WINS

Although the overall function of WINS has not changed significantly in Windows Server 2003, some additions to the management tools allow for increased functionality and capabilities:

• Advanced search capabilities for WINS databases Previous implementations of WINS had simplistic search capabilities that were limited to simple keyword searches of NetBIOS records in the database. The search engine for WINS has been updated in Windows Server 2003 to support more advanced search parameters, thus giving administrators more flexibility in searching for specific records.

• WINS pull record filtering and replication partner acceptance Instead of entire transfers of all records on other servers, replication can be limited to only those records owned by a specific server, thus excluding extraneous records from littering a WINS database.

In addition to these advances in Windows Server 2003, Windows 2000 introduced enhancements to WINS, such as an updated database engine, persistent connections, manual tombstoning, and other improvements.