What's This 'Internet' I Keep Hearing About? - Part Seven - Names, Not Numbers

When most people think of an 'Internet Address' they think of something like 'www.ocportal.com' rather than '69.60.115.116'. People relate to names with greater ease than numbers, so special computers that humans need to access are typically assigned names ('domain names') using a system known as 'DNS' (the 'domain name system').

All Internet communication is still done using IP addresses (recall '69.60.115.116' is an IP address). The 'domain names' are therefore translated to IP addresses behind the scenes, before the main communication starts.

At the core, the process of looking up a domain name is quite simple - it's a process of 'homing in' by moving leftwards through the name, following an interrogation path. This is best shown by example - 'www.ocportal.com' would be looked up as follows:

• Every computer on the Internet knows how to contact the computers (the 'root' 'DNS servers') responsible for things like 'com', 'org', 'net' and 'uk'. There are a few such computers and one is contacted at random. The DNS server computer is asked if they know 'www.ocportal.com' and will respond saying they know which server computer is responsible for 'com'.

• The 'com' server computer is asked it knows 'www.ocportal.com' and will respond saying they know which server computer is responsible for 'ocportal.com'.

• 'The 'ocportal.com' server computer is asked if it knows 'www.ocportal.com' and will respond saying that it knows the corresponding server computer to be '69.60.115.116'.
Note that there is a difference between a server computer being 'responsible' for a domain name and the domain name actually corresponding to that computer. For example, the 'ocportal.com' responsible DNS server might not necessarily be the same server as 'ocportal.com' itself.