# Load-Balancing Group Configuration

Load-balancing groups are a legacy method of configuring CE-side load balancing. It was the only method available before Release 7.1.0. Load-balancing groups enable you to configure attributes for a group that are inherited by the member shim interfaces.

Figure 120: CE-Side Load-Balancing Topology

In the topology shown in Figure 120, the two Ethernet ports on PE 1 (2/0 and 3/1) are connected to an 802.3ad-compliant switch, and comprise the set of candidate ports. Three VLAN subinterfaces are configured on each port. Load-balancing group 100 includes three Martini circuits, one for each pair of subinterfaces on the ports. That is, three circuits were created: one for the pair 2/0.1 and 3/1.10, one for the pair 2/0.2 and 3/1.20, and one for the pair 2/0.3 and 3/1.30. Each of the three Martini circuits connects to a remote PE router. The remote PE router receives and sends only a single VC label for each circuit.

Traffic from the switch can be received on all ports and sent over the appropriate Martini circuit. For example, traffic from CE 1 to be sent over Martini circuit 1 could arrive on port 2/0 or 3/1 and still be appropriately forwarded.

You configure each circuit for VLAN or S-VLAN subinterfaces that you create across a set of candidate Ethernet ports. The router distributes traffic from the core through the candidate ports used by the load-balancing group. If a port is disabled, traffic is redistributed to a working port.