Chapter Summary

The Domain Name System (DNS) defines the terminology, naming conventions, and protocols required to allow users to use host names. When a user refers to a host name, the host, called a DNS resolver, sends a DNS request to a DNS server. The server ultimately returns a response that tells the resolver the IP address that corresponds to that name.

Each company or organization should have a DNS server that is the authoritative DNS server for that domain. That DNS server can resolve names inside that domain. When that DNS server gets DNS requests for names in other domains, it asks for help from a root DNS server, which helps it locate the authoritative DNS server for the domain in which that name resides.

Although impractical today, a host could use a local host table, which is simply a list of host names and their IP addresses.