Networking problem with firewall and KVM

[Serge Hallyn]

Quoting Lorenzo Milesi (maxxer at ufficyo.com):
> it's really weird.
> I've done similar configuration with Xen in the past and never had problems. It's the first time I'm using Ubuntu 12.
> The only difference I left compared to other docs I found online was the standard virbr0 interface, which I now removed. That caused some iptables rules to be generated, but none was defaulting to reject. And right now, since when I removed the interface the rules have been removed, so iptables is totally empty.

So you bring up the host, all is well, you start up the kvm guest and
boom you lose access to the wan?

Can you show the xml for the guest, and the results of the following
with and without the guest running, of

	ifconfig -a
	brctl show
	netstat -nr
	traceroute google.com
# i know they're empty, but just for sanity
	iptables -L -t nat
	iptables -L -t mangle
	iptables -L -t security
	iptables -L