DNS on Windows Server 2003, 3rd Edition

Partial-Secondary Servers

In between a caching-only name server and a secondary name server is another variation: a name server that is a secondary for only a few of the local zones. We call this a partial-secondary name server (although probably nobody else does). Suppose movie.edu had 20/24-sized (the old Class C) networks (and a corresponding 20 in-addr.arpa zones). Instead of creating a secondary server for all 21 zones (all the in-addr.arpa subdomains plus movie.edu), we could create a partial-secondary server for movie.edu and only those in-addr.arpa zones the host itself is in. If the host had two network interfaces, its name server would be a secondary for three zones: movie.edu and the two in-addr.arpa zones.

Let’s say we scare up the hardware for another name server. We’ll call the new host zardoz.movie.edu, with IP addresses 192.249.249.9 and 192.253.253.9. We’ll create a partial-secondary name server on zardoz, with the configuration shown in Figure 9-5.

Figure 9-5. The DNS console showing a partial-secondary server

This server is a secondary for movie.edu and only 2 of the 20 in-addr.arpa zones. A “full” secondary would have 20 different zones (plus the three automatically created) under Reverse Lookup Zones.

What’s so useful about a partial-secondary name server? They’re not much work to administer because their configuration doesn’t change much. On a server authoritative ...