> Another site can't send mail to my site because the connection times
> out. I believe the connection may be timing out because of his DNS. I'd
> like to air my reasoning out here so that a) people who understand
tcpserver
> better can verify what I believe the man page is telling me, and b) people
> who understand DNS better can verify what I'm seeing in DNS.
Finally got this one solved. Posting the solution in case it bites
someone else.
My firewall passed DNS-UDP packets from the mail hosts, but not DNS-TCP.
The site in question had a large number of PTR records, which would cause a
reply large enough to be run over DNS-TCP instead of UDP. Thus, reverse
lookups worked for almost everyone, but not this site. Allowing DNS-TCP AND
UDP fixed the problem (and should have been the configuration to begin
with).
--
gowen -- Greg Owen -- [EMAIL PROTECTED]
