Subject: Re: Network stuff
To: John Nemeth <jnemeth@cue.bc.ca>
From: Manuel Bouyer <bouyer@antioche.lip6.fr>
List: port-i386
Date: 06/19/1998 11:38:51
On Jun 19, John Nemeth wrote
>      There's another problem.  DNS usually uses UDP.  I don't see how
> that could work through NAT, unless the NAT implementation has special
> handling for DNS.  The only NAT setup I've done has a fully functional
> DNS server on the NAT server.

No problem: request comes from 10.0.2.15/port xxxx to 205.216.36.20/port 53
You NAT box will remap this to a request from <you ppp adress>/port yyyy to
205.216.36.20/port 53. The DNS will then send back anserw from
205.216.36.20/port 53 to <you ppp adress>/port yyyy. The NAT box will map this
back from 205.216.36.20/port 53 to 10.0.2.15/port xxxx and forward this
UDP packet.
Of course, the NAT box chooses port yyyy in the list of dynamic unused ports,
or this will not work.

--
Manuel Bouyer, LIP6, Universite Paris VI.           Manuel.Bouyer@lip6.fr
--