[dns-operations] CNAME points to itself

Stephane Bortzmeyer bortzmeyer at nic.fr
Tue Jul 5 07:29:21 UTC 2016

On Tue, Jul 05, 2016 at 02:48:20PM +0800,
 yhpeng at orange.fr <yhpeng at orange.fr> wrote 
 a message of 16 lines which said:

> 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?

It wouldn't help, a rogue DNS zone operator could always run a
modified version (or simply another server) allowing this. A DNS
resolver MUST defend itself against the possibility of infinite

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