Re: [CentOS] CentOS-6.7, kvm bridges, virtual interfaces, and routes

Search for policy routing. Surprisingly, I cannot find anything about it in the RHEL6 docs.

You don't say how exactly you tried. It should be sufficient to edit rt_tables (maybe that's a step you missed? The actual number used doesn't matter) and add the route-eth1/rule-eth1 files on every host involved. I.e. no separate route/rule file shold be needed for the default interfaces.

I then also would like to configure each kvm guest of each host such that their traffic to the private network segment on the opposite host routes through the x-over cable via br0 whilst everything else goes out through br1 to the LAN and gateway.

ITYM ... x-over cable via br1 ... out through br0 ... ?