I have read some DNS guides and tried it. Rather complicated and hard to manage. I would leave it to using the domain providers or your hosting provider’s DNS system. At rackspacecloud; and i presume most DNS settings have similar setting options, heres how its set:

• you need 1x A record [which is IP],
• 1x CName record [which is www.mydomain.com],
• 1x MX record [which is mydomain.com; this allows asd@mydomain.com], and thats it.

if you need more sub domains you can add more CNames e.g. abc.mydomain.com

• A record
  • Name = mydomain.com;
  • Content = 123.45.67.89; [content is your ip address]
  • TTL = 300;
• CName record
  • Name = www.mydomain.com;
  • Content = mydomain.com;
  • TTL = 300;
• MX record: Name = mydomain.com;
  • Content = mydomain.com;
  • TTL 300;
  • Priority = 10 [if you use google apps, they will give you a huge list of 6 mx records, I know. its a pain. Enter them all by changing the Content, such as Content = aspx.googlemail.com]

Take a note of TTL which is time to live in seconds. 300 seconds would be 5 minutes. If DNS is changed it will take 5 minutes to propagate throughout the world. Normally people put 84600 which is 24 hours.

Option B: Setting up DNS using your Domain Host (such as GoDaddy)

In your domain, just set the IP address to point to your new server IP (given to you by your provider, Rackspace or Amazon. You can do this by going on to the machine and typing

> ifconfig