Symptom
Upon RSP FO the BFD session is DOWN due to the receipt of a Down SCN
Conditions
a) If BFD session was present for an ifh via Bundle RTR session/v4/v6 for BE10.
b) The IP-ARM registration for session ifh happens for both v4/v6 even though only v6 sessions are created.
c) So there are some changes that even before v4 session create BFD might receive v4 source address update. But that will never get updated in session DB.
d) If this happens then Bundle RTR session will be present without source address then after RPFO when it download session to agent.
e) While seeing this via bfd_db_session_update() in agent the sessions are moved to DOWN with reason as "PATH DOWN"
