I'm playing with KVM, and have three computers: My host and two guest, all running linux of course. The setup is like this:
Internet -- host -- virbr1 (private network) -- guest1 and guest2
virbr0 (default KVM network)-- guest1
In words I have a private network defined which uses virbr1, while the default NET'ed KVM network uses virbr0.
Now for the first question, I'm having troubles setting up the firewall. For startes, I'm trying to get guest1 and guest2 to talk to one another on the private network. The host can reach both guests on that network, but they can't reach each other. I've set up forwarding by echoing "1" into /proc/sys/net/ipv4/ip_forward, but without success. Anyone knows why the bridge virbr1 don't forward packets?
Btw, I'm using guarddog to manipulate iptables, so advice on how to get things working using guarddog would be even better.