Comment 21 for bug 1599329

Interestingly there is a kernel iptables drop message that mentions the instance's MAC on the node with the dhcp server. Could be related. It's the only drop on br-ex in the whole log.

http://logs.openstack.org/91/367191/2/check/gate-tempest-dsvm-neutron-dvr-multinode-full-ubuntu-xenial/7fd0e33/logs/syslog.txt.gz#_Sep_08_14_15_35