I had setup a bridge and got the same problem, but iptables was setup well. In my case the problem was lying in /proc/sys/net/bridge/. everything Everything inside had value "1", changed . Changing them to "0" solved the problem. This stopped ARP and problem was solvedbridge packets from beingpassed through the FORWARD chain. These settings can be placed inside /etc/sysctl.conf (Debian) so that they are persistent.