Refer to the exhibit.
AS 65500 is running OSPF as its IGP and has two eBGP connections to the Internet
provider AS 65501. The provider requires that you advertise all of the prefixes in AS 65500
to the provider as a single 192.168.12.0/22 route. Currently only Routers A and B are able to
reach the Internet. Which of the following additions to the configuration will solve this issue?
A.
RouterA(config)#ip cef
B.
RouterA(config)# ip route 192.168.12.0 255.255.252.0 null 0
C.
RouterA(config-router)#ebgp multihop 1
D.
RouterA(config-router)#redistribute ospf 1
E.
RouterA(config-router)#neighbor 192.168.14.253 next-hop-self
F.
RouterA(config-router)#neighbor 192.168.14.253 local-as 65500
Explanation:
The synchronization rule states “A BGP router should not use, or advertise to an external
neighbor, a route learned by IBGP, unless that route is local or is learned from the IGP”.
Notice that IGP here can be a static route.
In this case, unless there is an entry about network 192.168.12.0 in the routing table of
RouterA, RouterA will not advertise this network to its EBGP -> B is correct (even if this
static route points to Null0).
Note: Although this question states that OSPF is being used as IGP but for some reasons,
network 192.168.12.0/22 is not advertised to RouterA -> RouterA does not have this route in
its routing table.