Load balancing is not possible because BGP selects only a single best path to a destination among the BGP routes that are learned from the different ASs. In this scenario, achieving load balancing using BGP protocol is not an option (for a multi homed environment), so you can only do load sharing. Ii) BGP Load Sharing When Multi homed to Two ISPs through a Single Local Router Use a number between 1 and 6 for the paths argument. In order to make this change, include the maximum-paths pathscommand under the BGP protocol configuration. However, you can change the maximum number of parallel equal-cost paths that are allowed. By default, BGP chooses one best path among the possible equal-cost paths that are learned from one AS. This sample configuration uses the maximum-paths command. These links are terminated on one router at the local AS and on multiple routers at remote AS in a single-homed BGP environment. This scenario shows how to achieve load sharing in BGP when multiple links exist between a remote AS and a local AS. i) BGP Load Sharing When Dual-Homed to One Internet Service Provider (ISP) Through a Single Local Router If we have two or more ASs, a customized configuration is needed to distribute traffic across AS.

Paths with lower costs will carry more traffic and paths with higher costs will carry less traffic.īGP Load Sharing is a common scenario however it is usually done in two or more links connected to a unique Autonomous System (ISP). If unequal paths, the traffic is distributed inversely proportionally to the cost of the routes. This still bears the possibility of unbalanced forwarding. Load sharing is the forwarding process of a router to share the traffic if the routing table has multiple paths to a destination.

BGP Load Sharing When Multi homed to Two ISPs through Multiple Local Routers.

BGP Load Sharing When Multi homed to Two ISPs through a Single Local Router.

BGP Load Sharing When Dual-Homed to One Internet Service Provider (ISP) Through a Single Local Router.

In this article we will learn about load sharing and below are topics: eBGP (Flavour of BGP protocol) is the best answer which uses Load Sharing mechanism for incoming traffic by utilizing AS- Path attribute. Load Sharing works by splitting the traffic and then distributing the load across multiple links.

Cisco router dual isp load balancing