The value of tmnxOspfVirtNbrRestartHelperExitRc indicates the
outcome of the last attempt at acting as a Graceful restart
helper for the neighbor.
none No restart has yet been attempted.
inProgress A restart attempt is currently underway.
completed The last restart completed successfully.
timedOut The last restart timed out.
topologyChanged The last restart was aborted due to
a topology change.