Refer to the exhibit. By default, when RTB passes BGP advertisements from RTA about
network 192.168.2.0 to RTC, what address will be listed as the next-hop address? Select
the best response.
A.
10.1.1.1
B.
10.1.1.2
C.
192.168.1.49
D.
192.168.1.50
Explanation:
This is a rule for BGP advertisement:
“For EBGP, the next hop is always the IP address ofthe neighbor specified in the neighbor
command. For IBGP, the protocol states that the next hop advertised by EBGP should
be carried into IBGP“.
In this case, when RTA (in AS 65000, which is an EBGP for RTB) advertises a route to
RTB, it specifies its interface (192.168.1.50) as the next-hop. But when RTB passes this
advertisement to RTC, it specifies RTA interface (also 192.168.1.50) as the next-hop
(IBGP). This can cause some routing failures because if RTC does not know a way to reach
RTA interface via IGP (OSPF, EIGRP…), it will drop that packet. To fix this problem, add
the “neighbor 10.1.1.2 next-hop-self” command underBGP mode in RTB.