Lesson 6

Troubleshooting Name Resolution

4-63

domain that contains the name it is trying to resolve. The DNS server in Windows

Server 2003 comes preconfigured with root hints for the Internet root name servers, as

shown in Figure 4-18.

F04pm18

Figure 4-18

The Root Hints tab in a DNS server’s Properties dialog box

Off the Record

The addresses of the Internet root name servers rarely change, and it is

not likely that a Windows DNS server would be unable to contact even one of these servers,

unless someone modifies the root hints. It is more common for a network connectivity prob-

lem to be affecting the server’s communication with the root name servers.

Incorrect root hints are more likely to cause problems in a DNS namespace that is iso-

lated from the Internet and contains its own internal root. If this is the case, the person

who initially configured the DNS server probably forgot to add the internal root name

server to the list of root hints, or typed the root name server’s address incorrectly. Cor-

recting the root hints in the DNS console should resolve the problem.

It is also possible that the server is configured not to use recursion at all. Windows

Server 2003 DNS servers use recursion by default, but it is possible to prevent the

server from using recursion by selecting the Disable Recursion check box under Server

Options in the Advanced tab in the server’s Properties dialog box. You can also prevent

recursion when configuring a Windows DNS server to use forwarders. When you dis-

play a DNS server’s Properties dialog box, you can select the Do Not Use Recursion For

This Domain check box. This prevents the server from using any recursion, should the

forwarder be unable to resolve a name. If you require the server to use recursion, be

sure that these options are not selected.