During BGP configuration on a router that has peered with other BGP speakers, the BGP command aggregate-address 172.32.0.0 255.255.252.0 is issued. However, the peers do not receive this aggregate network in BGP advertisements. Also, the router does not have this aggregate network in its BGP table. Which option indicates a possible reason this command did not cause the router to advertise the aggregate network to its peers? Select the best response.
A.
Interface NULL 0 is likely shutdown.
B.
The BGP command no synchronization is missing.
C.
The BGP command no auto-summary is missing.
D.
Subnets of 172.32.0.0/22 do not exist in the BGP table.
E.
The IGP running on this router does not have network 172.32.0.0/22 installed.
F.
The next hop IP address must be a loopback address.
Answer: D
Explanation
A rule of aggregation is “Aggregation applies only to routes that exist in the BGP routing table. An aggregated route is forwarded if at least one more specific route of the aggregation exists in the BGP routing table.