I did a small investigation on this one and I found that tests are failing with error like:
2019-06-14 05:56:35.110 26575 DEBUG neutron.agent.linux.utils [-] Running command (rootwrap daemon): ['ip', 'netns', 'exec', 'test-26150a31-5291-4b93-9ac0-a8c143a680ae', 'ebtables', '-t', 'nat', '--concurrent', '-A', 'neutronMAC-test-veth0be0dc', '-i', 'test-veth0be0dc',
'--among-src', 'fa:16:3e:e6:dd:20', '-j', 'RETURN'] execute_rootwrap_daemon /home/cloud-user/neutron/neutron/agent/linux/utils.py:103
2019-06-14 05:56:35.129 26575 ERROR neutron.agent.linux.utils [-] Exit code: 255; Stdin: ; Stdout: ; Stderr: Unknown argument: '--among-src'.
So I checked manually:
$ sudo ebtables -t nat --concurrent -A OUTPUT --among-src fa:16:3e:e6:dd:20 -j RETURN
Unknown argument: '--among-src'.
And looked into man page where I found "BUGS" section:
The version of ebtables this man page ships with does not support the broute table. Also there is no support for
the among match. And finally, this list is probably not complete.
So it looks that this will simply not work and we have to workaround it somehow.
I opened bug agains RHEL for that https://bugzilla.redhat.com/show_bug.cgi?id=1720637
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.