If someone asks you to implement load balancing on equal-bandwidth parallel links between a pair of BGP routers, your first thought should be multihop EBGP session between loopback interfaces. Although this design is ancient and excruciatingly boring, it still has a few interesting twists, for example:
- Why do I need a multihop EBGP session?
- How do I detect the EBGP neighbor failure without using BGP timers (BFD does not work for multihop neighbors)?
Last but not least, an EBGP multihop session is vulnerable. You can use the neighbor disable-connected-check command to have a single-hop EBGP session with an IP address that is not directly connected.