Windows Internet Name Service
Windows Internet Name Service |
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In the example illustrated in Figure 7.20, a medium-sized company has two main sites (labeled Site 1 and Site 3) with 500 computers each, all connected through relatively high-speed links. The company also has more than 160 small branches. To save on the costs of the links, some branches act as concentrators for a region (such as Site 2).
Figure 7.20 A Typical WINS Deployment
The branches might have local WINS servers, but in most cases, they do not—there is simply no need for a separate server for each branch. Instead, the company adds regional WINS servers when the costs of registration and query traffic increase above the cost of deploying the additional server. When the link to a regional WINS server fails, local names can still be resolved by the broadcast mechanism.
The regional WINS servers are not required for this configuration to function correctly, but they do provide a cost optimization. From a network efficiency point of view, the company's system administrators should avoid deploying the regional servers whenever possible because they increase the convergence time. Administrators configure regional WINS servers (such as the one at site 2) as replication partners of the WINS servers in the main sites (sites 1 and 3). Clients in the main site are configured with the IP address of their local WINS server as primary and the IP address of the WINS server in the other main site as secondary. Clients in the regional branches are configured with the IP address of the regional WINS server as primary and the address of the closest main site WINS server as secondary.
Figure 7.21 shows the network configuration of another example company that is very different. The network serves a larger company with three sites, each with 5,000 users. The sites are connected with multiple T1 links. The number of users justifies a primary and a secondary WINS server at each site. The clients are configured with a local primary and secondary WINS server. Half of the clients have one local WINS server as primary and the other as secondary. The other half have exactly the opposite configuration. This balances the registration and query load over both WINS servers, and it provides a hot backup for maintenance purposes and in case of a calamity.
Figure 7.21 A Triangular WINS Deployment
The local WINS servers use a very short pull replication interval of 10 minutes, so all computers within the same building are reachable within 10 minutes of an address registration or change. The replication interval between the sites can be longer—about 30 minutes—because most users work with resources on their local servers.
