Path selection criteria used in BGP

In Border Gateway Protocol (BGP), the selection of the best path among multiple paths to the same destination is determined by a set of criteria known as path selection criteria. The following is a list of the most important BGP path selection criteria, in order of priority:

• Pick the route that has the most weight.
• Choose the route with the highest local preference if weight is not specified.
• Choose routes that began with this router.
• Choose the Autonomous System path that is the shortest.
• Select the path with the lowest origin code (lowest is I next is e, and last is?).
• If the same Autonomous System advertises the available routes, choose the path with the lowest MED.
• Opt for an EBGP route rather than an IBGP route.
• Choose the route that passes through the IGP neighbour with the lowest IGP metric.
• Pick the oldest route.
• Choose the path that passes through the neighbour with the smallest router ID.
• Select the path that passes through the neighbour with the smallest IP address