8.4.1 Load Balancing Overview

Load balancing is the practice of distributing increased traffic loads among multipaths to the same destination.It is implemented by routing control in the IP layer. This functionality limits the need for capacity upgrades by increasing bandwidth use through the aggregation of existing capacity.

This section covers load balancing at Layer 3.

The figures below illustrate load balancing using multipath routing, for scenarios involving one or many neighboring routers. In these figures, the switch uses hardware processing to relay packets from Network A to the servers in Network B over four paths at high speed.

Figure 8-12: Load balancing using multipathing (when a single neighboring router is used)

Figure 8-13: Load balancing using multipathing (when multiple neighboring routers are used)