A DNS record for both www and non-www websites

Question

For each website I have, I noticed that having just this A DNS record:

*.example.com   3600    A   0   192.1.2.3

will make http://example.com unavailable and having just this A DNS record:

example.com 3600    A   0   192.1.2.3

will make http://www.example.com unavailable.

Question: is it mandatory to have two A DNS records to support www and non-www

*.example.com   3600    A   0   192.1.2.3
example.com     3600    A   0   192.1.2.3

or is there a way to define both in one A DNS record?

---

PS: If it's mandatory to have two records, would you use:

www.example.com 3600    A   0   192.1.2.3
example.com     3600    A   0   192.1.2.3

or would you do it this way:

www.example.com 3600    CNAME example.com
example.com     3600    A   0   192.1.2.3

?

Solution 1

Short answer: Yes.

Longer: I would suggest you adding exactly www.example.com and not *.example.com unless you don't want to ever use any sub-domain like john.example.com and jane.example.com, etc....

Also, do not forget to configure your apache/nginx (which ever you use) to accept connections for both domain names.

Solution 2

To answer the second part of your question: For names I know will be served by the same machine for the foreseeable future I personally prefer defining one A record and then using CNAMEs as aliases for that record. That way I can change an address in one place and have everything move with it.

A typical example: A load balancer/reverse proxy might get an A record with the name lbtest.example.com to point at its IP address.

Each name served by that specific machine (example.com, www.example.com, foo.example.com) would get a CNAME pointing at lbtest.example.com.

Comments

[Basj]

Thank you @Bert fo your answer. I added a small PS at the end of the question, would you use one A and one CNAME, or two A records to handle both www and non-www?

[Bert]

Two A records, I would.