Hi everyone,

I have an IBM HS22 blade running KVM on Red Hat 6.2. This physical blade has 4 NICs and I'd like to use them in 2 bonds, each bond carrying certain VLAN traffic. From what I've read, it sounds like I have to use bridges to accomplish the VLAN tagging. So, does this mean I would have to configure each eth interface in a bond, then assign each bond to a bridge? Let me illustrate what I mean:

eth0 & eth1 --> bond0 --> br0

eth2 & eth3 --> bond1 --> br1


I've been trying to accomplish this and can't even seem to get the bonds to have connectivity. But if I use a single eth interface directly on a bridge (skipping bonds), then I'm able to get network connectivity without VLAN tagging.

I guess I'm just trying to gain an understanding of how networking works in KVM. If anyone can lend advice or point me in the direction of a clear How-To guide, that would be greatly appreciated. I've been trying to get this working for several days now. I'm not sure why it's so difficult to get two ethernet interfaces to work as a bonded interface and carry VLAN traffic to the VM guests.

Thanks

Very easy
first the bonding
eth0+eth1. Make sure you use a supported mode (modes 0 and 6 especially don't like to work under bridges, I recommend mode-4 if your switches allow for it)
then the bridging comes on top. So your diagram was correct:
If you also need to use vlan tags, then you need to place them on the bond, so that the bridges are in top of the tagged interfaces:

hope it makes sense, if not, look on the redhat user portal, there are KBs that describe this