Comment by neel-basu-z for RDO link providing an answer https://openstack.redhat.com/Neutron_... NOTE: It is important to do the network restart before setting up the router gateway below, because a network restart takes destroys and recreates br-ex which causes the router's interface in the qrouter-* netns to be deleted, and it won't be recreated without clearing and re-setting the gateway. # . keystonerc_admin # neutron router-gateway-clear router1 # neutron subnet-delete public_subnet You need to recreate the public subnet with an allocation range outside of your external DHCP range and set the gateway to the default gateway of the external network. # neutron subnet-create --name public_subnet --enable_dhcp=False --allocation-pool=start=192.168.122.10,end=192.168.122.20 --gateway=192.168.122.1 public 192.168.122.0/24 # neutron router-gateway-set router1 public

I've recreated network, router and subnets. Please check the additional outputs on https://gist.github.com/anonymous/67d1f967711d90a023bb . Now I see some ARP traffic on tcpdump. But still I cant ping the network on qdhcp namsespace from qrouter namespace and vice verse