Junos Format install on QFX5100 / QFX3500/ Ex9200

User needs to perform a format install on a qfx5100; noticed that he cannot do it following the standard EX procedure.

Newer Juniper devices do not support the older way of doing a format install, instead of that we need to use an install media image.

In case you need to format install this devices or make a backup of the file system you need to use an install media image and backup partition on an external flash drive.

This can be done using the following procedure:

This flash drive can be used to restore the device in case a format install must be done by putting the usb onto the switch and reloading it.

This can be run from any unix box that supports the dd command.

In case that the switch is “bricked” or that you do not have access to a unix machine; you can download the following software for windows.


Basically you need to specify the Flash driver letter, and the directory in which you have the install media image.

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James Palmer

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