Note: This topic applies to all EX Series Virtual Chassis except EX8200 Virtual Chassis. See Understanding Virtual Chassis Port Link Aggregation in an EX8200 Virtual Chassis for information about EX8200 Virtual Chassis.

You can combine physical Ethernet ports belonging to different member switches of a Virtual Chassis configuration to form a logical point-to-point link, known as a link aggregation group (LAG) or bundle. A LAG provides more bandwidth than a single Ethernet link can provide. Additionally, link aggregation provides network redundancy by load-balancing traffic across all available links. If one of the links fails, the system automatically load-balances traffic across all remaining links.

Similarly, if a Virtual Chassis member switch that has LAG member interfaces on multiple member switches fails for any reason, the traffic traversing the LAG can be redirected through the active member switch. This setup has benefits for failover purposes and can be especially beneficial in cases when a member switch needs to be inactive for some time.

You can configure any optical uplink port that can be used to connect EX2200, EX3300, EX4200, EX4500, or EX4550 switches together into a Virtual Chassis port (VCP). You can configure multiple optical uplink interfaces between two member switches in the same Virtual Chassis as VCPs. If you have configured two or more optical ports as VCPs connecting the same member switches, the optical uplink ports configured as VCPs automatically form a LAG provided the optical uplink ports are configured to operate at the same link speeds. Each LAG is assigned a positive-integer identifier called a trunk ID.

On EX2200 and EX2200-C switches only, you can also configure the RJ-45 interfaces, including built-in network ports with 10/100/1000BASE-T Gigabit Ethernet connectors and 1000BASE-T RJ-45 transceivers, into VCPs. On EX2200 and EX2200-C switches, a LAG that includes up to 8 interfaces configured as VCPs automatically forms. The LAG bundles includes all interfaces configured as VCPs, irregardless of whether the interfaces are optical transceiver interfaces, RJ-45 transceiver interfaces, or built-in network ports with 10/100/1000BASE-T Gigabit Ethernet connectors.

You can create an optical VCP LAG connecting any two member switches in any Virtual Chassis, including VCP LAG connections interconnecting different switch models in a mixed Virtual Chassis.

On an EX2200 switch only, you can also configure all RJ-45 interfaces, including built-in network ports with 10/100/1000BASE-T Gigabit Ethernet connectors and 1000BASE-T RJ-45 transceivers, on EX2200 and EX2200-C switches, into VCPs. The RJ-45 interfaces also automatically form a LAG when configured into VCPs.

Table 1 provides the maximum member link limit for each optical VCP LAG.

A LAG over uplink VCPs provides higher overall bandwidth for forwarding traffic between the member switches connected by the optical VCPs, faster management communications, and greater redundancy of operations among the members than would be available without the LAG. A LAG over uplink VCPs provides an additional Virtual Chassis link throughput for the switches.

See Setting an Uplink Port on an EX Series Switch as a Virtual Chassis Port (CLI Procedure) for information about configuring uplink ports as VCPs.

Note: The interfaces that are included within a bundle or LAG are sometimes referred to as member interfaces. Do not confuse this term with member switches, which refers to switches that are interconnected as a Virtual Chassis. It is possible to create a LAG that is composed of member interfaces that are located in different member switches of a Virtual Chassis.