[dns-operations] Weird TXT record

[Stephane Bortzmeyer]

On Wed, Jun 22, 2011 at 10:39:56AM +0100,
 James Stevens <James.Stevens at cdns.net> wrote 
 a message of 20 lines which said:

> I won't accept packets from someone unless they are announcing that
> subnet to me - would that work, or is the BGP too weird for it to be
> that simple?

It's called Strict Reverse Path Forwarding. RFC 3704. Section 2.2
discusses why it is not always a good idea.