I have a linux machine with with 2 physical network interfaces eth0 and eth1. There is a fault-tolerance (active-backup) bond created over these two interfaces. The bond0 has assigned IP address. eth0 and eth1 have no IP address assigned.
Everything is working OK. When link to eth0 goes down outgoing traffic is routed through eth1 and when eth0 goes up then linux switch back and uses eth0 for all outgoing traffic. So far so good.
I want to test if the path over eth1 is ok but do not want to break connection over eth0. Is there a way how to force kernel to use eth1 for outgoing traffic for some testing packet?