Origins of WINS

Whether your network uses DNS or WINS, name resolution is an essential part of network administration. Name resolution allows you to search your network and connect to resources using names such as "myprinter" or "ourfileserver" rather than memorizing a host's Internet Protocol (IP) address. Remembering IP addresses would be even more impractical when using Dynamic Host Configuration Protocol (DHCP) for address assignment because the assignments may change overtime.

WINS is supported by DHCP services. Whenever the computer you named "fileserver01" is dynamically assigned a new IP address, the change is transparent. When you connect to fileserver01 from another node, you can use the name fileserver01 rather than the new IP address because WINS keeps track of the changing IP addresses associated with that name.

WINS was created to solve the problems of broadcast-based name resolution and the burden of maintaining LMHOSTS files. With LMHOSTS files, name resolution information is stored in a static format, making it a management-intensive chore to maintain. With broadcast-based name resolution systems such as NetBIOS, larger networks became more congested as hosts come online and broadcast messages to all other nodes to resolve IP addresses. In addition to the congestion, these broadcasts cannot cross routers, meaning that names can only be resolved locally.

WINS is built on a protocol, defined by an Internet Engineering Task Force (IETF) Request for Comments (RFC) that performs name registration, resolution, and deregistration using unicast datagrams to NetBIOS name servers. This allows the system to work across routers and eliminates the need for an LMHOSTS file, restoring the dynamic nature of NetBIOS name resolution and allowing the system to work seamlessly with DHCP. For example, when dynamic addressing through DHCP creates new IP addresses for computers that move between subnets, the WINS database tracks the changes automatically.

The complete Windows 2000 WINS system includes a WINS server, clients, proxy agents, a WINS database, and a WINS management console. Each of these is described in this chapter.

WINS is compatible with the protocols defined for NetBIOS name servers (NBNS) in RFCs 1001 and 1002, so it is interoperable with other implementations of these RFCs. Another RFC-compliant implementation of the client can talk to the WINS server and, similarly, a Microsoft TCP/IP client can talk to other implementations of the NBNS. However, because the WINS server-to-server replication protocol is not specified in the standard, the WINS server does not interoperate with other implementations of NBNS. Data cannot be replicated between the WINS server and the non-WINS NBNS. Without replication, name resolution cannot be guaranteed.