Networking problem with firewall and KVM

[Lorenzo Milesi]

> Can you give more details on the host networking setup?

eth0 -> br0
eth2 -> br1

eth0 is connected to the lan interface, eth2 to the modem


> This doesn't make sense to me.  

to me neither :)

> Let's say eth1 is the WAN nic which is
> bridged into br1.  Without extra iptables rules, traffic from the
> host
> is going to flow over eth1 without going through the kvm host first,
> right?

I don't know the details of bridging but yes, it sould be that way.

> So we really need to see your whole setup.


/etc/network/interfaces (relevant parts):
auto eth0
iface eth0 inet manual

# Rete locale
auto br0
iface br0 inet static
	address 192.168.1.xx
	netmask 255.255.255.0
	gateway 192.168.1.1
	dns-nameservers 192.168.1.1 8.8.8.8
	bridge_ports eth0
        bridge_stp off
        bridge_fd 0
        bridge_maxwait 0

auto eth2
iface eth2 inet manual

# Rete INTERNET
auto br1
iface br1 inet manual
	bridge_ports eth2
        bridge_stp off
        bridge_fd 0
        bridge_maxwait 0



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.

thanks
-- 
Lorenzo Milesi - lorenzo.milesi at yetopen.it

GPG/PGP Key-Id: 0xE704E230 - http://keyserver.linux.it