Graceful Restart on the Receiving
During session startup, BGP
whether they have the graceful restart capability. When BGP restarts, the receiving
router retains routes received from the restarting router and marks those routes stale.
The receiving router continues to advertise the restarting router as if it was fully
functional until one of the following events occurs:
- The restarting router sends the EOR marker, indicating the
end of a routing update and the end of the graceful restart.
- The restart timer defined by the restarting router
- The stale-route-time timer defined on the receiving router
If the receiving router receives RIB updates and the EOR marker
before the timers expire, it updates the local RIB and deletes any
stale entries. If either of the timers on the receiving router expires
before the receiving switch receives the EOR marker from the restarting
switch, all stale routes are deleted.