I found a small bug on kilo version: ping the external network ip, clear external-gateway and then set the external-gateway back, the ping connection is not recoverd due to conntrack.
here is the detailed operations:
1. make sure a vm is connected to a router: "router1", and the router is connected to an external network.
2. ping the external network in a vm, it should be successful:
# ping 8.8.8.8
3. clear the external-gateway, now the ping connection is dropped.
# neutron router-gateway-clear router1
4. set the external-gateway back, "public" is an external network.
# neutron router-gateway-set router1 public
Now, I found the ping connection is not recovered, my investigation shows this is due to conntrack state issue.
we have similar issue with DVR https:/ /bugs.launchpad .net/neutron/ +bug/1456624 /review. openstack. org/#/c/ 199196/
And there is a change submitted for that https:/
This might help in your debug.