How to upgrade Juniper EX4200 switch software

      1.       Format DOK (disk-on-key), with enough space, to FAT32

      2.       Copy the software image (jinstall-ex-4200-11.3R2.4-domestic-signed.tgz)  into the DOK

      3.       Plug the DOK into the USB port of the switch in the backside

      4.       Enter shell mode [you will need root password]

user@switch> start shell % su Password: root@switch%

       5.       Mount the DOK

mount_msdosfs /dev/da1s1 /mnt

       6.        Copy the image file to temporary directory

cp /mnt/ jinstall-ex-4200-11.3R2.4-domestic-signed.tgz /var/tmp

       7.       Return to operational mode

cli

       8.       Start upgrade process

request system software add /var/tmp/ jinstall-ex-4200-11.3R2.4-domestic-signed.tgz