Recovering From U-boot Mode

Have you ever found your Junos device stuck in the "U-boot" mode ( => ) before? Mario Costa explains how to recover from this situation.

When in this state your Junos image has of course "magically disappeared" and your heart skips an unhealthy beat. Here is a survival guide that will aid you in getting Junos installed from a TFTP/FTP server on your network.

Step 1:

Firstly, you need to get your environment variables set, which is basically assigning the following: Management Port IP address (ipaddr), Gateway IP address (gatewayip), TFTP/FTP Server IP address (serverip)

setenv ipaddr 192.168.1.1

setenv netmask 255.255.255.0

setenv gatewayip 192.168.1.254

setenv serverip 192.168.1.100

save

Step 2:

Secondly, reboot the device (boot command) to then access the "Loader" prompt. During the reboot process you will be presented with the following output:

Hit [Enter] to boot immediately, or space bar for command prompt.

After pressing the space bar key on your keyboard you gain access to the Loader prompt:

loader>

Step 3:

Thirdly, you need to install (via TFTPBOOT) the JunOS image on your device:

loader>install tftp://192.168.1.100/junos-srxsme-11.1R1.10-domestic.tgz

Step 4:

Wait patiently as the Junos device boots. After the boot process has completed successfully you should have Junos installed on your internal flash and a "healthy device" up and running again.