Hello together, we have one problem here, it is more an idealistic problem: We have an PC - let us call him PC_1 - with one Ethernet adapter. This one is connected to the WWW with this adapter and also via several iptunnels to an specific PC_2 out there. Through these tunnels now IP packets with private IPaddresses reach PC_1. There they will now be routed by the default route to the WWW and so they leave eth0 and will be masqueraded ... So on PC_1 we did: iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE defining the tunnel back to PC_2: ip tunnel add tunl-4 mode ipip local <IP_form_PC_1> remote <IP_from_PC_2> tos inherit ip address add 192.168.104.1 dev tunl-4 ip link set dev tunl-4 up ip route add default dev tunl-4 table 4 this is not so important now: tc class add dev eth0 parent 20:1 classid 20:2 cbq bandwidth 1000000 rate 9000 allot 1514 weight 900 maxburst 20 avpkt 1000 isolated bounded tc qdisc add dev eth0 parent 20:2 sfq quantum 1514b perturb 15 tc filter add dev eth0 parent 20:0 protocol ip pref 2 u32 match u8 2 0xff at 21 flowid 20:2 what should be put back in the tunnel to PC_2: ip rule add fwmark 2 pref 2 table 4 ip route flush cache example for a ping: iptables -A PREROUTING -t mangle -d <private_IP_that_had_come_out_of_the_tunnel, eg 192.168.199.10> -s <destinationIP_of_server_in_the_WWW> -p icmp -j MARK --set-mark 2 iptables -A PREROUTING -t mangle -m mark --mark 2 -j ACCEPT NOW the problem is that the returning IPpackets from the server in the WWW has the destination of PC_1 so the PREROUTING fails :O| So we had the idea to set up a dummy0 device and send all demasqueraded IPpackets to this dummy, because we know this must be a private IP: ip address add 192.168.4.1 dev dummy0 ip link set dev dummy0 up ip route add 192.168.199.0 dev dummy0 So the idea was now that the PREROUTING should fetch the incoming packets from dummy0, but it did not work :o( Do you have an idea to map the PREROUTING to a special (virtual) device - in this case the dummy0 - or to change the order of Demasquerading and PREROUTING? I know that this whole set-up will work if I use a 3rd machine for the MASQUERADING, but this is really not smart .... Thanks a lot for some hints and regards from Aachen, Marc, Heiko and Colin -- Marc Vorwerk Researcher EED/R/N Ericsson Eurolab Deutschland GmbH Mobility Applications Laboratory - Networks Tel: +49 2407 575 4814 Fax: +49 2407 575 400 Mobile: +49 173 543 14 73
