BGP4+ Multipath for Load Balancing

BGP4+ selects only one best path for each IPv6 prefix it receives before installing it in the IP routing table. For load balancing across different paths, use the maximum-paths command to enable BGP4+ multipath.

You can select iGP paths, eBGP paths, or a combination of both.

The following attributes of parallel paths must match for them to be considered for multipathing:

Weight
Local Preference
Origin
AS-Path Length
MED
Neighbor AS (eBGP multipath)
AS-PATH match (for iBGP multipath)
IGP metric to BGP next hop