A network receives two eBGP-learned paths to a destination. Path X has an AS path length of 3 after prepending by the remote, Path Y has AS path length 1. All other attributes equal. Which path will BGP prefer?

BGP prefers Path Y because it has a shorter AS path length. A shorter AS path indicates fewer autonomous systems traversed to reach the destination, which is generally considered a more direct and therefore preferred route. AS path length is a key attribute in the BGP best path selection algorithm, evaluated early in the process. Path X's longer AS path, even due to prepending, makes it less desirable. MED (Multi-Exit Discriminator) is considered later in the BGP best path algorithm, after AS path length. Neighbor IP is also considered much later, primarily as a tie-breaker.