In BGP, which attribute helps influence outbound path selection within an AS?

In BGP, which attribute helps influence outbound path selection within an AS?

• A. AS_PATH
• B. NEXT_HOP
• C. LOCAL_PREF
• D. MED

Answer: (C)

Local preference is the BGP attribute used to influence outbound path selection within an AS. This value is set by the local administrator to indicate which exit point should be preferred when multiple egress routes exist to reach the same destination. Higher LOCAL_PREF values win, so you can steer traffic toward a preferred exit point inside your AS. It stays within the AS (non-transitive), meaning it isn’t advertised to other ASes. If two routes have different LOCAL_PREF values, the one with the higher value is chosen regardless of other factors. Only if LOCAL_PREF is equal do other attributes come into play. AS_PATH records the sequence of ASes the route traversed and is used as a later tie-breaker. NEXT_HOP is simply the address of the next router to send packets to the destination; it affects reachability but not the internal preference between outbound exit points. MED is used to influence inbound path selection from neighboring ASes, not outbound path selection inside the local AS.

Local preference is the BGP attribute used to influence outbound path selection within an AS. This value is set by the local administrator to indicate which exit point should be preferred when multiple egress routes exist to reach the same destination. Higher LOCAL_PREF values win, so you can steer traffic toward a preferred exit point inside your AS. It stays within the AS (non-transitive), meaning it isn’t advertised to other ASes. If two routes have different LOCAL_PREF values, the one with the higher value is chosen regardless of other factors. Only if LOCAL_PREF is equal do other attributes come into play.

AS_PATH records the sequence of ASes the route traversed and is used as a later tie-breaker. NEXT_HOP is simply the address of the next router to send packets to the destination; it affects reachability but not the internal preference between outbound exit points. MED is used to influence inbound path selection from neighboring ASes, not outbound path selection inside the local AS.