DNS can strike fear into even hardened web veterans (take our boss as an example), but it’s really nothing particularly complicated. I’m going to provide a quick guide, which hopefully by the end, you should feel a lot more comfortable using DNS.

First things first; ‘DNS’ stands for domain name server(s). A domain name server’s sole responsibility is to translate web addresses (www.example.com) into IP addresses (123.123.123.123). The process is like this:

• You type in a web address
• This request is sent to a DNS server (the IP of which is stored by either your ISP or overridden by settings on your own computer).
• The DNS server will then translate the web address starting with the end of the domain name (e.g. .com or .co.uk)
• Once an IP is found, the request is passed to the DNS for the TLD which locates the IP for the everything before the last dot.
• The request will keep getting passed to different DNS servers until it reaches the destination at which the website can be found.

This is all theory and is unlikely to affect how you update your own DNS settings however. So, lets run through an example of using DNS to move a domain name:

• You would initiate a transfer with your new registrar and complete any authorisation checks etc.
• Once the domain was under the control of the new registrar, you would have at least 2 options to point the domain to where you wanted.
• The first option would be to add nameserver records to the domain’s config. This would tell the registrar where the DNS was for your website.
• The other option would be to use the registrar’s nameservers and add an ‘A’ record to the domain’s config. This record is very simple and takes an IP as the value.

The pain about DNS is that they can’t update immediately once you make changes as they get queried millions of times a day. In order that the servers don’t crash, DNS servers have to cache the location of websites for up to 48 hours. When the cache is cleared, new requests will trigger the DNS server to re-translate to the IP address.

So, although it can be frustrating to deal with DNS and it is likely to be a necessary evil for most web admins, the best thing you can do is plan for changes that you are going to make in advance of making them.

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