AddPath unit-tests sometimes hangs during execution

Seen sporadically both in CI and local environment

https://jenkins.opendaylight.org/releng/job/bgpcep-verify-boron-mvn33-openjdk8/352/console

07:04:46 Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 43.058 sec - in org.opendaylight.protocol.bgp.rib.impl.AddPathBasePathsTest
07:04:47 Running org.opendaylight.protocol.bgp.rib.impl.AddPathNPathsTest
12:49:15 Build timed out (after 360 minutes). Marking the build as failed.
12:49:15 [ssh-agent] Stopped.
12:49:15 Build was aborted

Console output is attached. HOLD_TIMER_EXPIRED message is reported indicating that somehow keepalives are not getting exchanged correctly (e.g. lock-up in sending/receiving messages)