In case when P device is a penultimate hop for some transit RSVP LSPs or bypass LSPs, following log message can be seen when link flaps on the way of these RSVP LSPs or bypass LSPs:

Nov 14 19:32:48 routername rpd[85651]: RPD_RSVP_NBRDOWN: RSVP neighbor 192.168.1.1 down on interface None nbr-type Node, neighbor timeout

In these log message, 192.168.1.1 - is a direct RSVP neighbor. However the session with this direct RSVP neighbor is not affected. Transit LSPs, traversing through device with such logs and ending at neighbor 192.168.1.1, can be affected.

Check directly connected RSVP session with IP in the log message (in example above it is 192.168.1.1): if the session is fine then such logs indicate the transit RSVP session flapping probably because of the link flap.

2023-12-27 : Draft

2023-12-27 : First version