Domain Name System

I just posted this explanation of domain names, IP addresses and DNS to CYN and thought it might be useful to someone else. Its very raw and unedited due to being a forum post rather than a well thought out article but the content is reasonable I think.

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Here's a quick explanation of the domain name system (although a quick Google search will probably explain better than I ever could).

Let's start with a couple of definitions -

domain name - the name people type into their web-browsers or email software.
IP address - the numeric address (in the form 123.123.123.123) of a computer on a network connection (in this case network can mean Internet)
DNS (domain name system) - the system of the Internet that allows domain names to be converted into IP addresses.

Basically, think of domain names as people, IP addresses as phone numbers and DNS as a phone book.

You want to call your friend John - you want to go to www.google.com
You look in the phone book to find his phone number - you (or rather your web-browser) looks it up in the DNS
You now know the phone number to call John with - your web-browser now knows the number it needs to contact to show you www.google.com

So it works like this -

You register a domain name with company X and, by default, they will set it up to point to an IP address of their's which will have a load of advertising on it. If you have signed up for hosting with them then it will be the IP address of whatever server is going to provide your hosting.

This new information is then submitted into the domain name system and eventually propagates to all the other name servers. This bit can take a little while which is why you're told to be patient. It can happen within 5 minutes but can take up to 24 hours or so.

If you haven't signed up for hosting with company X then you edit the DNS information for yourself to tell it where your hosting is (by providing an IP address for it to point to). This is called the A record. There is a separate (MX record) for the mail server that will handle email sent to name@domain.com.

So what does all this tell you?

Basically that you can find a new hosting provider and update the DNS entries of your domain names to point to the new host and (within 24 hours) be back in business.

As ever, your mileage may vary, but that's a simple round up of how this stuff works. If anyone has any questions or wants a hand to deal with any of this stuff feel free to let me know and I'll see what I can do.