By default, IOS does not allow you to load balance between multiple paths received from different AS numbers. This commands changes this default behavior. I have seen some customers using it to load balance between two default routes (0/0) received from two upstream ISPs.
If it is doing only to outbound traffic, Then what is the process to do for incoming traffic?
@Joseph W. Doherty wrote:
This is also applicable in case of DC fabric, ( leaf spine architecture ).
In case one have different AS number at Spine and Leaf layer, even when you have multipath ; add path features enabled. Only one path is installed in routing table. As the router sees the AS - Path different on the 2 routes recieved ( Spine 1 & Spine 2 )
To enable BGP to install multiple path, all values must be equal. ( including AS path / length ) so if we have 2 different AS path, it does not consider them equal
This command allows BGP to deviate from standard rules, and install both prefixes even when they are received from different AS path
Hope that helps
By default, there is no load balancing in IOS with BGP but this command will enable the Load balancing between two different routes.