Which of the following is a valid BGP configuration for router R2?

Question

Options

• Agroup "Conf-eBGP" peer-as 65541 neighbor 10.16.10.1 exit group "Member-AS" neighbor 10.16.10.6 peer-as 65542 exit exit no shutdown
• Bgroup "Conf-eBGP" peer-as 65541 neighbor 10.16.10.1 exit group "Member-AS" neighbor 10.16.10.6 peer-as 65540 exit exit no shutdown
• Cgroup "Conf-eBGP" peer-as 65540 neighbor 10.16.10.1 exit group "Member-AS" neighbor 10.16.10.6 peer-as 65542 exit exit no shutdown
• Dgroup "Conf-BGP" peer-as 65540 neighbor 10.16.10.1 exit neighbor 10.16.10.6 exit exit no shutdown

• A
  74% (23)
• B
  10% (3)
• C
  3% (1)
• D
  13% (4)

Explanation

Option A correctly assigns each neighbor to its proper remote AS - 10.16.10.1 to AS 65541 (via the "Conf-eBGP" group) and 10.16.10.6 to AS 65542 (via the "Member-AS" group) - matching the network topology where R2 resides in AS 65540 and peers with two distinct external ASes.

Why the distractors fail:

• B is wrong because it assigns 10.16.10.6 a peer-as of 65540, which is R2's own AS - you cannot peer eBGP with yourself, making this an impossible session.
• C is wrong because it swaps the peer-as on the first group, assigning 10.16.10.1 to AS 65540 (again R2's own AS) instead of the correct 65541.
• D is wrong structurally: it uses a single group for both neighbors but only assigns one peer-as at the group level, leaving 10.16.10.6 without a valid peer-as definition - invalid for eBGP sessions that require distinct remote AS values per peer.

Memory tip: In eBGP configs, peer-as always points outward - it's the neighbor's AS, never your own. If you spot your own AS number assigned as a peer-as in a group, that option is immediately eliminated.

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