BGP Load Sharing in Single / Multihomed Environments [Cisco]

Cisco - Load Sharing with BGP in Single and Multihomed Environments: Sample Configurations Load sharing allows a router to distribute the outgoing and incoming traffic among multiple paths. The paths are derived either statically or with dynamic protocols, such as:

• - Routing Information Protocol (RIP)
• - Enhanced Interior Gateway Routing Protocol (EIGRP)
• - Open Shortest Path First (OSPF) Protocol
• - Interior Gateway Routing Protocol (IGRP)

By default, Border Gateway Protocol (BGP) selects only a single best path and does not perform load balancing. This document shows how to perform load sharing in different scenarios with the use of BGP. For additional information about load balancing, refer to How Does Load Balancing Work?.


Content:

1. Load Sharing with the Loopback Address as a BGP Neighbor
2. Load Sharing When Dual-Homed to One Internet Service Provider (ISP) Through a Single Local Router
3. Load Sharing When Dual-Homed to One ISP Through Multiple Local Routers
4. Load Sharing When Multihomed to Two ISPs Through a Single Local Router
5. Load Sharing When Multihomed to Two ISPs Through Multiple Local Routers