Password recovery on Juniper SRX 100

One day when I arrived at the office I did find a little blue box on my desk, which turned out to be a Juniper SRX 100 firewall. While looking at this tiny device I remembered that a colleague of my told me he would give a Juniper SRX to me.

And since I really like hardware, even the small boxes 🙂 I’m very pleased he brought this SRX, and give it to me.. So a big thanks!

Up for a challenge

At the end of the day, well actually later that evening, after I had something to eat, it was time to power the SRX on. The original adapter was missing, but since I got a box full of adapters , finding the right adapter shouldn’t be a problem. And sure enough.. after a while I came up with an adapter which delivers 12V and 1.5A.

The adapter has its ground (-) on the outerside, and the plus (+) on the middle pin.

The SRX needs 12V and 1A, so this adapter will do just fine. After searching for a console cable (a standard Cisco console cable just works) I connected the SRX, plugged in the console and power, and switched the device on.

After a few moments I was greeted with a banner, telling me the device once belonged to Ziggo. And that also told me right away that a simple password recovery is not going to work.

The SRX has a reset button, which can be used to reset the password..  However through a configuration setting this button can be disabled.. And since this device once belong to Ziggo, I know for sure that they disabled this button. Of course I tried the reset button.. and yes.. it did nothing at all.

So how to get into this device….

Using an USB device

Their is only one way around this.. and that is: installing / upgrading the SRX. This can be done by putting a Junos image (.tgz file) on a USB device, or putting the image on a tftp server.

The first problem is: how to get a Junos file.. Well I don’t have a support contract with Juniper.. so I had to google for a while but finally found a torrent file.

This is however not recommended, for one: it’s illegal. And two: the image can be tempered with, and could hide some nasty stuff.  I don’t like the illegal stuff, and in my lab I can perfectly live with the possible security risk.

Anyway, once I got the software I formatted a USB stick, and copied the junos image. After inserting the usb stick in the SRX 100 I interrupted the boot sequence. This can be done by hitting the spacebar while connected to the serial console at boot time.

Once the boot process was interrupted I was looking for a command “install”. Unfortunately this command was not present in the u-shell.

So I rebooted pressing the reset button while booting, and this activated a second boot partition. This version had the install command.

From there I tried o load the image from the USB stick.. but that didn’t work. Well not to worry.. I got a tftp server.. Copied over the junos image to my tftp server and started a install by tftp..

 

And that worked 🙂 After completing the upgrade.. I can logging with the root user and no password.