Question

An IBGP-enabled PE router in AS 65000 receives two paths to the same external prefix 203.0.113.0/24 from two different route reflectors. Both paths have identical weight, local preference, AS-path length, origin code, and MED. Both are learned via IBGP (neither is locally originated or EBGP). The BGP next-hop of path 1 (10.0.0.5) is reachable via an IGP metric of 30, while the BGP next-hop of path 2 (10.0.0.9) is reachable via an IGP metric of 20. Assuming 'bgp bestpath compare-routerid' is NOT configured and both paths are still valid, which path will BGP select as best and why?

Accepted Answer

Path 2, because it has the lowest IGP metric to the BGP next-hop

Answer

Path 1, because with equal attributes the oldest received path is preferred

Answer

Path 2, because it is compared using the lowest neighbor router ID first

Answer

Path 1, because IBGP paths always prefer the numerically lower next-hop address