In which of the following BGP-related events is an End-of-RIB (EOR) message sent? (Choose
two.)
A.
Following a link flap in the BGP speaker’s AS
B.
During initial convergence.
C.
Following a Route Processor Switchover.
D.
Just before sending a CEASE message to tear down the session.
E.
During capability negotiation
Explanation:
The Peer Router must signal the completion of the initial routing update by sending the End-of-RIB
marker (discussed below)
While continuing to forward packets, the Peer Router refreshes the Restarting Router with any
relevant BGP updates. The Peer Router indicates completion of this process by sending an Endof-RIB (EOR) marker. The EOR marker for IPv4 is a BGP update message that is of the minimum
length—23 bytes. The EOR does not contain any routes to be added or withdrawn. Essentially, it
is an “empty” update, whose sole purpose is to indicate that all available routes have been sent.
The EOR marker helps speed convergence, because it allows the router to begin best-path
selection as quickly as possible, without waiting for the timer to expire.
Once the Restarting Router has received all available routes from each peer, it can conduct bestpath selection, and send any updates to its Peer Routers. The Restarting Router will also use the
EOR to indicate the completion of this process.