BGP Path Attributes: Shortest AS Path

After AIGP Path Attributes, the next deciding factor is evaluating the AS Path of a route.

The AS Path attribute typically corresponds to the number of AS hops are needed to reach a destination. The shorter the AS path, the more preferred it is.

There can be times when AS paths are not relative to the number of hops, and that is with AS Prepending. Typically network organisations add their AS number multiple times to the AS Path to make a route less preferred to alternative paths that they may offer.

Prepending AS paths is a common method for service providers on influencing inbound traffic to their network. Different to local preference and weight where outbound traffic is influenced.