Comment 22 for bug 1013199

Hmm so either something has changed or my testing before was not 100% accurate.

Using the below configuration I am unable to ping anything. Additionally I can't talk to any resources via the default gateway (I have confirmed I can do this without bridging in play), however I just noticed that I can connect to the system via our admin network which is source via 172.31.252.0/22 and has a different gateway from our default gateway.

Once again here is my current /etc/network/interfaces

# The loopback network interface
auto lo
iface lo inet loopback
    post-up /usr/sbin/service dnsmasq start

#auto eth0
#iface eth0 inet static
# address 10.42.1.28
# netmask 255.255.254.0

auto eth0
iface eth0 inet manual
        address 0.0.0.0

auto br0
iface br0 inet static
        address 10.42.1.28
        netmask 255.255.254.0
 network 10.42.0.0
        bridge_ports eth0
        bridge_fd 0
        bridge_stp off

#auto br0
#iface br0 inet static
# address 10.42.1.28
# netmask 255.255.254.0
# network 10.42.0.0
# bridge_ports eth0
# bridge_fd 9
# bridge_hello 2
# bridge_maxwait 12
# bridge_stp off

Here is the output of ip route:
default via 10.42.0.1 dev br0 src 10.42.1.28
10.42.0.0/23 dev br0 proto kernel scope link src 10.42.1.28
172.31.240.0/21 via 10.42.0.2 dev br0
172.31.252.0/22 via 10.42.0.2 dev br0