[dns-operations] CNAME points to itself
johnl at taugh.com
Tue Jul 5 21:30:48 UTC 2016
>I have found that CNAME can be setup to point to itself (at least in
>BIND9 it can be).
>www.itest.com. 300 IN CNAME www.itest.com.
>should this be disabled?
There's no point. How would you prevent this?
--- (on your nameserver) ---
www.foo.com. 300 IN CNAME www.bar.com.
--- (on another nameserver on the other side of the planet) ---
www.bar.com. 300 IN CNAME www.foo.com.
As others have noted, you have to break CNAME loops when you resolve
names. You can't prevent them.
More information about the dns-operations