Network domains and mail addresses

Large networks may have thousands of systems connected to them. A domain name addressing scheme is used to specify system addresses in a way that humans can understand.

The top level domain for the UK is uk. This domain has several sub-domains: ac (for academic) and co (for commercial).

The ac domain has many sub-domains, based on the name of the organisations within it. The sub-domain for the University of Hull for example is hull.

If the organisation has a large number of systems, then the organisational domain might also contain sub-domains, each of which contains a number of systems. This is often done on a departmental or service basis.

The mail address for any system can be given as a series of domains, each of which is separated by a dot (full stop).

For example, the full mail address to a user on a particular system might look like this:

   john@ubik.ucs.ed.ac.uk

Reading from left to right, this is the mail address for the user known as john on the system called ubik. This system is in the organisational sub-domain ucs, (University Computing Service) which is in the organisational domain ed (Edinburgh).

This organisation is located in the ac (academic domain) for the national domain uk (United Kingdom).

This site maintained by umk@astroa.physics.metu.edu.tr