linux - KVM-Guests can't get past bridge - no internet connection

I'm running a backported KVM on a Debian Squeeze. ATM the KVM-Guest can't connect to the internet through the bridge I have set up. The guests can reach each other, the host but nothing outside. I can neither ping, nslookup or do anything to a remote address. The guest are configured to have a static IP. When I didn;t have the bridge but a virtual bridge (the KVM-default) the guest could connect fine. After setting up the bridge things broke, so I think the problem lies there.

# The loopback network interface
auto lo br0
iface lo inet loopback

# Bonding Interface
auto bond0
iface bond0 inet static
address 10.XXX.XXX.84

netmask 255.255.255.192
network 10.XXX.XXX.64
gateway 10.XXX.XXX.65
slaves eth0 eth1
bond_mode active-backup
bond_miimon 100
bond_downdelay 200
bond_updelay 200

iface br0 inet static

    bridge_ports eth0 eth1
    address 172.xxx.xxx.65
    broadcast 172.xxx.xxx.127
    netmask 255.255.255.192
    gateway 172.xxx.xxx.65
    bridge_stp on
    bridge_maxwait 0

Thanks in advance for your help !

Answer

Ok, silly me - as it turns out the problem was that the interface and the gateway had the same IP.