Configure BGP To Select Multiple BGP Paths

You can configure BGP to select multiple non-multi-hop EBGP or IBGP paths as active paths. Selecting multiple paths allows BGP peerings to load-balance traffic across an AS-confederation boundary. The JUNOS BGP multipath supports the following:

• Load-balancing across multiple links between two routers belonging to different ASs
• Load-balancing across a common subnet or multiple subnets to different routers belonging to the same peer AS
• Load-balancing across multiple links between two routers belonging to different external confederation peers
• Load-balancing across a common subnet or multiple subnets to different routers belonging to external confederation peers

To configure a BGP multipath, include the multipath statement:

multipath; 

You can configure BGP multipath for all peers in a group (at the [edit protocols bgp group group-name] level), or for an individual peer (at the [edit protocols bgp group group-name neighbor address] level). For routing instances, include the statement at the [edit routing-instances routing-instance-name protocols bgp group group-name] hierarchy level and the [edit routing-instances routing-instance-name protocols bgp group group-name neighbor address] hierarchy level.