> > There is no need to use multiport because you only DNAT 1 > port : smtp. > > But that should not be a problem. > > > > iptables -t nat -A OUTPUT -p tcp --dports smtp \ -j DNAT > > --to-destination 192.168.12.56 > > > if I try it without the multiport option i get the following > error.. > > [root@posjia0h01 root]# iptables -t nat -A OUTPUT -p tcp > --dports smtp -j DNAT --to-destination 192.168.12.56 iptables > v1.2.5: Unknown arg `--dports' > Try `iptables -h' or 'iptables --help' for more information. Sorry, that should be "--dport", not "--dports". > this is strange... > > > Ive got another mailserver 172.24.128.56 .. > now if I put that rule in > > iptables -t nat -A OUTPUT -p tcp -m multiport --dports smtp > -j DNAT --to-destination 192.168.12.56 > > and if I try telnet to any mail server on the internet , i connect to > 192.168.12.56 (Which should happen on 172.20.128.56) So if the rule works on 172.24.128.56, it should also be correct for 172.20.128.56. > [root@poscpt0h01 root]# telnet 196.31.155.18 25 Trying > 196.31.155.18... > Connected to 196.31.155.18. > Escape character is '^]'. > 220 c ESMTP Sendmail 8.12.8/8.12.8; > Fri, 8 Apr 2005 > 17:30:45 +0200 prxsaa0z02.ipnetwork.co.za is 192.168.12.56 I suppose ? > is there noway to make it connect directly to 196.31.155.18, > but using 192.168.12.56 as a gateway I think you'd need a smtp proxy to do that (right now you're using 192.168.12.56 as a mail-gateway because it forwards mail from other mailservers.) Perhaps if you run a smtp proxy on port 26 or so, and forward other mailservers to that port (192.168.12.56 is already running a mailserver on port 25) : iptables -t nat -A OUTPUT -p tcp --dport smtp \ -j DNAT --to 192.168.12.56:26 And let the smtp proxy connect to an internet MTA on port 25. But this way you still don't connect directly to the receiving MTA. Gr, Rob ********* DISCLAIMER ********* De informatie in dit E-mail bericht is uitsluitend bestemd voor de geadresseerde. Verstrekking aan en gebruik door anderen is niet toegestaan. Door de elektronische verzending van het bericht kunnen er geen rechten worden ontleend aan de informatie. TTP staat niet in voor de juiste en volledige overbrenging van de inhoud van een verzonden E-mail, noch voor tijdige ontvangst daarvan.
