Understanding Virtual Chassis Hardware Configuration on an EX4200 Switch

Virtual Chassis is a feature in Juniper Networks EX4200 Ethernet Switches that allows you to interconnect two or more EX4200 switches, enabling them to operate as a unified single high bandwidth switch. You can interconnect a maximum of 10 EX4200 switches through the dedicated 64-Gbps Virtual Chassis ports (VCPs) or the uplink module ports configured as VCPs to form a Virtual Chassis composed exclusively of EX4200 switches. All EX4200 switch models support Virtual Chassis, and you can interconnect different models, offering a range of port configurations, within the same Virtual Chassis.

On the EX4200-24Fswitch, network ports configured as VCPs can also be used to interconnect the switch.

EX4200 and EX4500 switches can be connected together into the same Virtual Chassis to form a mixed EX4200 and EX4500 Virtual Chassis. You can interconnect EX4200 and EX4500 switches through the dedicated Virtual Chassis ports (VCPs) to form a mixed Virtual Chassis.

The number of EX4200 and EX4500 switches that can be interconnected into a mixed Virtual Chassis depends on the Junos OS release running on the switches.

• Junos OS Release 11.1—A mixed Virtual Chassis supports up to two EX4500 switches and up to eight EX4200 switches. EX4500 switches must always be configured in the master and backup roles.
• Junos OS releases 11.2 and 11.3—A mixed Virtual Chassis supports up to two EX4500 switches and up to eight EX4200 switches. The same type of switch must act in the master and backup roles. If an EX4200 switch is configured in the master role, for instance, an EX4200 switch must also be configured in the backup role.
• Junos OS Release 11.4 and later—A mixed Virtual Chassis supports up to ten total EX4200 and EX4500 switches. Any switch can be configured in any role in any configuration. If an EX4200 switch is configured in the master role, for instance, an EX4200 or an EX4500 switch can be configured in the backup role.

The Virtual Chassis configuration includes designation of a master switch and a backup switch, with all other switches in the configuration designated as "line card" role switches. Virtual Chassis operation is managed through the master switch. Each switch in the Virtual Chassis is assigned a unique identifier that is displayed on the switch LCD.