On Sun, 29 Jun 2003, Greg A. Woods wrote:
> Likewise please remember that any one given address may have many names
> via the Reverse DNS (i.e. multiple PTRs are valid and necessary). If
> your DNS graph doesn't have a complete set of bi-directional links
> between your A records and your PTR records then your DNS graph is
> broken and your reverse DNS is useless for all but the most trivial of
> applications.
I'm trying to understand this conversation about reverse DNS;
I haven't read and understood all of the relevant RFCs.
If I understand what Greg is saying, services like dyndns are
fundamentally broken, since while the control the A record for your
name they cannot take control of the PTR record for your number ?
Actually they seem to be acknowledging this in
http://www.dyndns.org/services/dyndns/faq.html
"# How can I change my hostname in IRC to my dyndns.org host?"
and "My IP currently resolves to some name provided by my ISP. Can I
change that to my dyndns.org host/domain?"
Since these services are becoming popular, I fear that you need
to make clear the distinction between the way that the the internet
*should* work (RFCs, best practice etc.),
and the way that a significant portion of it does work.
Personally I can't see any excuse to run an SMTP *service*
(both incoming and outgoing) without a proper static IP address,
If you only have a dynamic IP address, you should be sending
through your ISPs smarthost.
However from several correspondents on this list it appears that
in some areas it appears to be difficult to buy connectivity with
either a reliable SMTP smarthost or a static IP address which is
not stuck in some DUL-registered piece of IP-space.
--
Dr. Andrew C. Aitchison Computer Officer, DPMMS, Cambridge
A.C.Aitchison@??? http://www.dpmms.cam.ac.uk/~werdna
