Because the canonical name and its alias can belong to different zones, the CNAME record must always be entered as a fully qualified domain name. NameSurfer checks that the canonical name really is an existing domain name, and issues a warning if the name does not exist.

CNAME records are useful for setting up logical names for network services so that they can be easily relocated to a different physical host. For example, it is common to define www.company.com as an alias for the machine running the company's WWW server.

The DNS protocol places a number of restrictions on the use of CNAME records:

• A name with a CNAME record may not have any records other than NameSurfer internal records, such as HTXT and HTML.
• Other records that "point" to domain names, such as NS, MX and PTR records, may not point to an alias. Instead, they should point directly to the canonical name.