https://unix.stackexchange.com/questions/272146/packets-not-moving-through-linux-ethernet-bridge
# do not query iptables for packet routing
echo 0 > /proc/sys/net/bridge/bridge-nf-call-iptables
# no additional processing for multicast packets
echo 0 > /sys/devices/virtual/net/br0/bridge/multicast_querier
echo 0 > /sys/devices/virtual/net/br0/bridge/multicast_snooping