Must iBGP neighbors be directly connected to form an iBGP session?

• A. Yes, they must be directly connected to form an iBGP session
• B. No, they can be reached via static routes or an internal routing protocol
• C. Only loopback addresses can be used
• D. They must be EBGP peers first

Answer: (B)

In iBGP, what matters is IP reachability between the two routers inside the same AS, not a direct physical link. The BGP session is a TCP connection between the two neighbor IP addresses, so as long as there is a route to the other side’s address, the session can be established. This is commonly done by using loopback addresses for stability, with update-source set accordingly and reachability provided by an internal routing protocol or static routes. If there’s no path to the neighbor IP, the session won’t form. EBGP, by contrast, is typically directly connected, but that’s a separate case.