[Mimedefang] validating 'possibly forged' helo IP's?
David F. Skoll
dfs at roaringpenguin.com
Thu Jan 12 13:15:02 EST 2006
WBrown at e1b.org wrote:
>> 1. There is only one ptr record per IP.
> Not true. I was testing that on my internal DNS:
Try adding 150 PTR records for a given IP address and watch all hell
break loose. :-)
(The large reply will make the DNS server want to fall back to TCP,
which is blocked by a lot of firewalls whose admins forget (if they
ever knew) that DNS can run over TCP as well as UDP.)
Regards,
David.
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