What information needs to be gathered in order to configure BGP?

• A. The AS numbers for your own network and all remote AS, the IP addresses of all neighbors involved and finally the networks that are to be advertised into BGP
• B. Only the networks to be advertised
• C. Only the neighbor IP addresses
• D. Only the remote AS numbers

Answer: (A)

BGP configuration hinges on three essential pieces of information. You must know your own AS number, the IP addresses of the neighbors you will peer with (and, if using non‑directed or loopback-based peering, the appropriate update-source configuration), and the remote AS numbers of those neighbors. This lets you establish the BGP session (via the neighbor IPs and AS relationship) and determine whether it’s an iBGP or an eBGP peer. At the same time, you need to specify which prefixes you want to advertise into BGP—those networks or routes you originate (or redistribute) so they are shared with your peers. Without any one of these elements, the BGP setup can’t proceed: you’d either have no session to form, no awareness of who to connect to, or no routes to announce.