Dropping flows on the the physical bridges causes networking to drop. It's one of the two places that still causes networking to drop when OVS agent is restarted. The other is that the patch port between br-int and br-tun is being deleted and rebuilt during startup.
This issue prevents no-downtime upgrades. It has been fixed in upstream and backported to stable/liberty branch. As there is not known plan for next stable RHEL OSP 8 release, the relevant patches are going to be backported proactively.
*** Bug 1343106 has been marked as a duplicate of this bug. ***
The code tested in latest OSP8 - openstack-neutron-7.0.4-7.el7ost.noarch
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.