[libvirt] networking with VMs on two nodes

I have two nodes and on each several virtual machines running under KVM/qemu. I've set up the default-network on each node and so I can: 1.) ping from host do guest 2.) ping from guest to host 3.) ping from guest tu guest But all this is only possibe on each node by itself. What I need now is network connection between a VM on node 1 to another VM on node 2. How to setup this? When both nodes are fine every node runs a few guests. But when one node goes down, all guests have to be run on the remaining node. mfg ar -- Hier könnte keine Signatur stehen.