A sub-domain is a way to hand off authority to another administration. Setting a sub-domain involves mostly telling where the DNS which manages this sub-domain is located. This is a two step process. First, you must define which machines are managing the sub-domain. Next, you must give the IP numbers of those machines, if they are part of the sub-domain. A DNS of a domain need not be part of the domain it is managing.
Some facts first...
Perform these steps...
DNS advertisingenter dns.sub.foo.com and ftp.sub.foo.com.
Now your DNS knows two things: Which machine(s) is(are) responsible for the sub-domain sub.foo.com, and, how to reach it. This information combination is often referred to as the glue record.
It is not necessary to setup a complete sub-domain just to have
a sub-category of machine. Suppose that for a project, you want to
refer to two machines as ftp.project.foo.com and www.project.foo.com.
You can simply define these machines' IPs using the
screen. The information will be dispatched in the