BGP selects a path based on which component?

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

Answer: (B)

BGP decides which route to use by looking at the attributes attached to each possible path. These path attributes describe various qualities of the path, such as AS_PATH, NEXT_HOP, LOCAL_PREF, MED, and others, and they encode the routing policy and reachability information the router should apply. The BGP best-path algorithm compares these attributes for all candidate paths and picks the one that offers the most desirable attribute set according to its defined rules (for example, preferring routes with higher LOCAL_PREF, shorter AS_PATH, etc.). Because the decision rests on the whole collection of attributes rather than any single one in isolation, the concept that best fits the mechanism is the attributes themselves.