BGP4+ multipath

The BGP4+ multipath feature can be used to enable load-balancing across different paths.

BGP4+ selects only one best path for each IPv6 prefix it receives before installing it in the IP routing table. If you need load-balancing across different paths, you must enable BGP4+ multipath using the maximum-paths command under IPv6 address family configuration mode.

IBGP paths and EBGP paths can be exclusively selected, or a combination of IBGP and EBGP paths can be selected.

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