$ 0 0 Try the links below: http://www.juniper.net/documentation/en_US/junos12.3/topics/task/installation/virtual-chassis-ex4200-ex4500-software-cli.html https://www.juniper.net/documentation/en_US/junos/topics/task/installation/qfx-series-software-upgrading-nssu-virtual-chassis-cli.html