I've got the following setup: debian linux stable kernel 2.2.19 ipchains 1.3.9, 17-Mar-1999 ip utility, iproute2-ss991023 internal if: 3: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 100 link/ether 00:50:04:31:9e:7d brd ff:ff:ff:ff:ff:ff inet 192.168.0.9/24 brd 192.168.0.255 scope global eth0 external if: 4: eth1: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 100 link/ether 00:50:04:ea:54:f1 brd ff:ff:ff:ff:ff:ff inet 62.98.35.177/29 brd 62.98.35.183 scope global eth1 inet 62.98.35.178/29 brd 62.98.35.183 scope global secondary eth1:0 masquerading works fine for 62.98.35.177 and i'd like to masquerade smtp from the internal network with the aliased ip 62.98.35.178. I've set up things as described in "12. Netfilter & iproute - marking packets" of the "Linux 2.4 Advanced Routing HOWTO" (with adaptions): ip addr add 62.98.35.178/29 broadcast 62.98.35.183 label eth1:0 dev eth1 ipchains -I input -i eth0 -s 192.168.0.9/255.255.255.0 -p tcp --dport ssh -m 1 # seems ok, ipchains -L shows hits ip rule add fwmark 1 table mail.out # seems ok ip route add default via 62.98.35.182 dev eth1 src 62.98.35.178 table mail.out # seems to be the weak point (I know "dev eth1:0" doesn't work because ip doesn't handle labels) - i'm not shure about the correct use of "src" ipchains -I forward -j MASQ -i eth1:0 -s 192.168.0.9/255.255.255.0 # ipchains -L shows NO hits How do i add the route for table mail.out to route for "eth1:0" in order to masquerade with 62.98.35.178? If this is not possible, is there another solution to get the desired behaviour (masquerading smtp with a diffrent address, routing for the same interface as other masqueraded traffic)? Thanks for your help Christof Marti