Looks like we merged [1] too soon, and despite external events handling during migration revert now being handled correctly in Nova with the merger of [2], there's something else broken, perhaps at the Neutron level, that prevents test_server_connectivity_cold_migration_revert from consistently passing. Until we figure out what that "something" is, I've proposed to skip the test in tempest [3] and filed a bug for it [4]. The bug is filed under Neutron, but that's more of a placeholder based on preliminary guessing. We can easily change it to Nova or some other component once we understand better what's going on. [1] https://review.opendev.org/#/c/663405/ [2] https://review.opendev.org/#/c/667177/ [3] https://review.opendev.org/#/c/670848/1 [4] https://bugs.launchpad.net/neutron/+bug/1836595