15.4. DNS Configuration Files
The following files are common to all DNS server configurations. Rather than repeat them multiple times, they are presented here for general reference.
15.4.1. The Forward Zone File for the Loopback Adaptor
The forward zone file for the loopback address never changes. An example file is shown in Example 15.4.1. All traffic destined for an IP address that is hosted on a physical interface on the machine itself is routed to the loopback adaptor. This is a fundamental design feature of the TCP/IP protocol implementation. The loopback adaptor is called localhost.
15.4.2. The Reverse Zone File for the Loopback Adaptor
The reverse zone file for the loopback address as shown in Example 15.4.2 is necessary so that references to the address 127.0.0.1 can be resolved to the correct name of the interface.
15.4.3. DNS Root Server Hint File
The content of the root hints file as shown in Example 15.4.3 changes slowly over time. Periodically this file should be updated from the source shown. Because of its size, this file is located at the end of this chapter.