Name service with WINS and DNS

The Windows Internet Name Service (WINS) is Microsoft's implementation of a NetBIOS name server (NBNS). As such, WINS inherits much of NetBIOS's characteristics. First, WINS is flat; you can have only simple machine names such as inca, mixtec, or navaho, and workgroups such as PERU, MEXICO, or USA. In addition, WINS is dynamic: when a client first comes online, it is required to report its hostname, its address, and its workgroup to the local WINS server. This WINS server will retain the information so long as the client periodically refreshes its WINS registration, which indicates that it's still connected to the network. Note that WINS servers are not workgroup- or domain-specific; they can contain information for multiple domains and/or workgroups, which might exist on more than one subnet.

Multiple WINS servers can be set to synchronize with each other. This allows entries for computers that come online and go offline in the network to propagate from one WINS server to another. While in theory this seems efficient, it can quickly become cumbersome if several WINS servers are covering a network. Because WINS services can cross multiple subnets (you'll either hardcode the address of a WINS server in each of your clients or obtain it via DHCP), it is often more efficient to have each Windows client, regardless of the number of Windows domains, point themselves to the same WINS server. That way, only one authoritative WINS server will have the correct information, instead of several WINS servers continually struggling to synchronize themselves with the most recent changes.

The currently active WINS server is known as the primary WINS server. You can also install a secondary WINS server, which will take over if the primary WINS server fails or becomes inaccessible. Both the primary and any other WINS servers will synchronize their address databases on a periodic basis.

In the Windows family of operating systems, only a server edition of Windows NT/2000 can act as a WINS server. Samba 2.2 can function as a primary WINS server, but cannot synchronize its database with other WINS servers. It therefore cannot act as a secondary WINS server or as a primary WINS server for a Windows secondary WINS server.

WINS handles name service by default, although Microsoft added DNS starting with Windows NT 4 Server. It is compatible with DNS that is standard on virtually every Unix system, and a Unix server (such as the Samba host) can also be used for DNS.

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