Load Balancing in BGP Networks

Good reference: Load Balancing in BGP Networks

Below are the copy from the link:

Fact #1: Load-balancing is always unidirectional
Fact #2: Not all Load-Balancing Mechanisms are Equal

External BGP Load Balancing
The true BGP-only EBGP load balancing is configured with the maximum-paths router configuration command and allows a BGP router with multiple EBGP sessions to load balance the traffic toward destinations received in EBGP updates.


IBGP Load Balancing
Option #1: Use next-hop-self
Option #2: External OSPF routes

Route Reflectors killed Load Balancing
Each BGP router selects a single best route (even though it might use more than one for packet forwarding) and propagates it to its BGP neighbors. A route reflector might thus use multiple IBGP routes and load balance between them, but its clients would only receive a single route.