Domain Name Server (DNS)

Domain Name Server (DNS)

The Domain Name Server (DNS) is a little know but very important part of the Internet. It maintains a list of all domains for which it is responsible. In this way, no single server is responsible for storing the name and IP address of every domain. When you register a domain, the registrar will also require that you enter at least two (2) DNS servers. If you have chosen to use the registrar for hosting, it will most likely default to those servers. However, if you choose to use a hosting company that is not also the registrar, you will have to enter the DNS servers for that hosting company. Most hosting companies will freely offer this information so you can enter it when you register your domain.

Name servers will often follow a convention to quickly identify them. For example, if you are hosting with www.myhost.com, their name servers might be:

ns1.myhost.com

ns2.myhost.com

Domain Name Server

The ns1 and ns2 stand for Name Server 1 and Name Server 2. There is no limit to the number a domain can have, but you must have at leas two (2). This is because name servers are almost always placed apart from one another. In this way, if something happens to one (server crash, power outage, etc.) another can still route traffic to your domain (assuming the web host is up and running and serving requests). This redundancy is designed to prevent outages and give you the best chance of keeping your domain up and accessible to the public.

Sub-Domain

Each Internet domain can be divided into an unlimited number of sub-domains. However, in practical terms, there are a few that are often created and maintained by the Domain Name Server (DNS) and web host. They are: