Selecting Multiple Equal-Cost Active Paths
You can configure BGP to select multiple equal-cost EBGP or IBGP paths as active paths. Selecting multiple paths allows BGP peerings to load-balance traffic across an AS-confederation boundary. The Junos OS BGP multipath supports the following:
- Load balancing across multiple links between two routing devices belonging to different ASs
- Load balancing across a common subnet or multiple subnets to different routing devices belonging to the same peer AS
- Load balancing across multiple links between two routing devices belonging to different external confederation peers
- Load balancing across a common subnet or multiple subnets to different routing devices belonging to external confederation peers
To configure a BGP multipath, include the multipath statement:
To disable the default check requiring that paths accepted by BGP multipath must have the same neighboring AS, include the multiple-as option.
For a list of hierarchy levels at which you can include this statement, see the statement summary section for this statement.
