Chapter 10. Domain Name System (DNS)

Terms you'll need to understand:

Berkeley Internet Name Daemon (BIND)
/etc/resolv.conf
/etc/named.conf
Fully qualified domain name (FQDN)
in.named
Name resolution
Primary server
Resource records
Root domain
Secondary server
Top-level domain
Zone of authority

Concepts you'll need to master:

Explain the purpose of DNS in a network environment.
Explain how to configure a primary and secondary DNS server and a DNS client.
Given DNS server output for a problem scenario, identify strategies to resolve the problem.

Domain name system (DNS) is the mechanism by which IP addresses are resolved from domain names and vice versa. The primary use for DNS is on the Internet, where it resolves any hostname to its relevant IP address. For example, you could navigate to Sun's Web site by typing in www.sun.com . After you type in this DNS name, Internet DNS servers resolve this name to Sun's IP address, which is returned to your computer so that you navigate to it. This chapter describes the basics of DNS: how to configure a server and a client as well as how to troubleshoot DNS problems.

You wouldn't need DNS if you only communicated with a small number of hosts on your local network. The /etc/inet/hosts file would contain the necessary information to resolve IP addresses from hostnames.