Ubuntu 12.04 Server - eth0 1Gbps NIC eth1 10Gbps NIC - all traffic using eth0?
Solution 1:
You can restrict interfaces to only respond to ARP broadcasts for addresses configured on the interface itself (rather than any on the system) via the following:
sysctl net.ipv4.conf.eth[num].arp_filter=1
eg, in this case:
sysctl net.ipv4.conf.eth0.arp_filter=1
sysctl net.ipv4.conf.eth1.arp_filter=1
Make the change permanent by adding the lines (minus the sysctl command) to /etc/sysctl.conf