irc channel is better than an IM program see you there On 5/9/05, Taylor, Grant <gtaylor@xxxxxxxxxxxxxxxxx> wrote: > > I want to route all outgoing port-25-traffic produced by the clients > > over ppp1. The rest schould take the default route over ppp0. > > > > I used the following command: > > > > iptables -A PREROUTING -p tcp --dport 25 -t mangle -i eth0 -j ROUTE > > --oif ppp1 > > This seems reasonable enough. > > > But the source addresses of the packets are wrong as "tcpdump -ni ppp1" > > shows: > > > > 01:20:24.422756 IP 192.168.0.4.32825 > 160.45.10.13.25: S > > 2020082843:2020082843(0) win 5840 <mss 1460,sackOK,timestamp 266850[|tcp]> > > > > 192.168.0.4 is the IP adress of the client which tried to connect to the > > mailserver 160.45.10.13.25. > > > > Masquarding is done to 192.168.0.0/24: > > > > # iptables -t nat -L POSTROUTING > > Chain POSTROUTING (policy ACCEPT) > > target prot opt source destination > > MASQUERADE all -- 192.168.0.0/24 anywhere > > > > My default route is set to ppp0. > > > > So, how can I replace/masquerade the 192.168.0.4 by the official IP > > address of ppp1? > > It looks like there might be a chance that traffic that goes out ppp0 and ppp1 are matching your one POSTROUTING rule. Is there a reason that you are not specifying an interface the traffic is going out to match against? I.e. > > iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE > iptables -t nat -A POSTROUTING -o ppp1 -j MASQUERADE > > I'm wondering if there is not some confusion in the kernel / routing code as to which source IP to use when going out ppp1. > > > Grant. . . . > > -- Glaucius Djalma Pereira Junior glaucius@xxxxxxxxx
