I'm still trying to solve an arp problem I have with a host that has 2 NIC's connected to the same network, same subnet. I need to make sure that arp responses only appear on either of the interfaces depending on where the arp request originated. This would require the use of /proc/sys/net/ipv4/conf/all/arp_filter and source routing I did find a confirmation of this in the kernel mailing list http://hypermail.idiosynkrasia.net/linux-kernel/archived/2002/week16/0458.html but I'm having trouble setting up the routes.I used the following script to test it but it fails when trying to set the second network route with an RTNETLINK file exists. IF1=eth0 IF1=eth1 P1_NET=192.168.1.0/24 P2_NET=192.168.1.0/24 P1=192.168.1.1 P2=192.168.1.1 IP1=192.168.1.95 IP2=192.168.1.99 T1=200 T2=201 ip route add $P1_NET dev $IF1 src $IP1 table $T1 ip route add default via $P1 table $T1 ip route add $P2_NET dev $IF2 src $IP2 table T2 ip route add default via $P2 table $T2 ip route add $P1_NET dev $IF1 src $IP1 ip route add $P2_NET dev $IF2 src $IP2 ip route add default via $P1 Can anyone point out my (probably simple) mistake? I'm assuming it's in my understanding of how to set this. Regards Geoff