Understanding Software Upgrade in a Virtual Chassis Configuration
A Virtual Chassis configuration can be composed of multiple EX 4200-series switches and each member switch is running JUNOS software packages. For ease of management, the Virtual Chassis configuration provides flexible methods to upgrade software releases.
A new software release can be upgraded to the entire Virtual Chassis configuration or to a particular member in the Virtual Chassis configuration through a CLI or J-Web command. A user can add software packages to either a single member of the Virtual Chassis configuration or to all members of the Virtual Chassis configuration at the same time.