On Thu, 2005-05-19 at 21:44 +0800, Mark Quitoriano wrote: > here's how i did mine > iptables -t nat -A PREROUTING -d xxx.xxx.xxx.xxx -p tcp -j DNAT > --to-destination 10.0.0.1 > > iptables -t nat -A POSTROUTING -d 10.0.0.1 -j SNAT --to xxx.xxx.xxx.xxx > > because the firewall has different ip than my mail server > You are forwarding it twice Is 10.0.0.1 the internal interface of the firewall (that contains -d xxx.xxx.xxx.xxx) or is it a seperate machine If it is on the same machine, try this (assuming you have a FORWARD rule too): iptables -A FORWARD -i $EXTIF -p tcp --dport 25 -m state \ --state NEW,ESTABLISHED,RELATED -j ACCEPT iptables -A PREROUTING -t nat -p tcp -d $EXTIP --dport 25 \ -j DNAT --to xxx.xxx.xxx.xxx ($EXTIF is the external insterface {eth0, eth1, etc.}, $EXTIP is the external IP address) > On 5/19/05, Peter Farrow <peter@xxxxxxxxxxx> wrote: > > If you're doing true port forwarding, the internal server should see the > > ip address of the external machine in its logs. > > > > This is how my machines log that do this, I use this type of entry in > > iptables: > > > > iptables -t nat -A PREROUTING -p tcp --dport 80 -i eth1 -j DNAT --to > > 10.198.0.17 > > > > P. > > > > > > Johnny Hughes wrote: > > > > >On Thu, 2005-05-19 at 21:08 +0800, Mark Quitoriano wrote: > > > > > > > > >>i'm having a problem viewing logs on forwarded ports from the firewall > > >>to another server, i forwarded mail(port 25) from the firewall to an > > >>internal server. The problem is when i try to view the logs it just > > >>shows the firewall ip as the sender and not the original sender. > > >> > > >> > > >> > > >> > > >In reality, the firewall may be making the connection to the internal > > >server... and not the external machine. Especially if the internal > > >server is on a 192.168.x.x or 10.x.x.x network and you are connecting > > >via NAT. If that is the case, the external machine is connecting to the > > >firewall and the firewall is connecting to the internal server. > > > > > > > > >------------------------------------------------------------------------ > > > > > >_______________________________________________ > > >CentOS mailing list > > >CentOS@xxxxxxxxxx > > >http://lists.centos.org/mailman/listinfo/centos > > > > > > > > _______________________________________________ > > CentOS mailing list > > CentOS@xxxxxxxxxx > > http://lists.centos.org/mailman/listinfo/centos > > > > -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: This is a digitally signed message part Url : http://lists.centos.org/pipermail/centos/attachments/20050519/10046e94/attachment.bin