*.mydomain.com - A record or CNAME?

Question

Some people are saying use an A record and others a CNAME for a catch all subdomain.

Which should I use and why?

Answer 1

If you have multiple domain that points to the same site:

With A record: every of your domain points to the IP of your site, when your change your server's IP, you will need to update multiple time.

With CNAME: every of your domain points to a CNAME, when your server's IP change, you will only need to update the A record of that CNAME.

If you have a domain that doesn't belongs to you, or you don't have the control of what it will be pointing to, you can only use CNAME.