ietf-mxcomp
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Re: Questions about DNS lookups in DMP and FSV

2004-03-10 19:19:11

In <700EEF5641B7E247AC1C9B82C05D125DA7B7(_at_)srv1(_dot_)fecyk(_dot_)ca> 
"Gordon Fecyk" <gordonf(_at_)pan-am(_dot_)ca> writes:

It is my understanding that DMP requires you to fetch a TXT record
from _smtp-client.$FQDN and also an A record at
$REV-ADDRESS.$ADDRESS-TYPE._smtp-client.$FQDN.  [...]

Doesn't this mean that DMP [...] require a minimum of 2 DNS queries?

More like a maximum of two, minimum of one[1].

Ok, so DMP doesn't require you to fetch *both* the TXT record and the
A record?  Doesn't the TXT just say that "yes, this domain uses DMP"?
Don't you have to look up the A record also to see if the IP address
is allowed or not?


                                                DMP got a little worse, with
a maximum of four queries, when a receiver queries for hostnames as well as
domain names.  If a receiver were prepared to sacrifice Store and Forward,
that got back down to a maximum of two.

Hmmm...  I don't understand this part, but maybe I just need to read
the DMP spec closer.



-wayne