Macro 32 Ramblings

How to recover root password for Junos versions 4.X or above

How to recover root password

Summary of steps:

• Get console access
• Power up the system
• Enter pathname
• The system will boot up
• Configuration Mode

• For routers running Junos 5.X and above
  1. Reboot the system
  2. From console, interrupt the boot routine:

             Hit [Enter] to boot immediately, or any other key for command prompt.
             Booting [kernel] in 9 seconds...
      
             < Press the space bar at this point > 
      

  3. Enter into single-user mode:

             Type '?' for a list of commands, 'help' for more detailed help.
             ok  boot -s
     
     
     

  4. If you have the following system output, enter recovery, hit enter and skip to step 8.

     Otherwise continue with next step.

             System watchdog timer disabled
             Enter full pathname of shell or 'recovery' for root password recovery or RETURN for /bin/sh: recovery
     
     

  5. Enter the shell:

             System watchdog timer disabled
             Jan  1 00:36:47 init: /etc/spwd.db: No such file or directory
             Enter full pathname of shell or RETURN for /bin/sh:  
        

  6. Mount the virtual file systems (for Junos 5.4 and above, it is not necessary to mount the jbase package, however the other packages still need to be mounted):

             NOTE: to go to multi-user operation, exit the single-user shell (with ^D)
             # cd /packages
             # ./mount.jbase
             Mounted jbase package on /dev/vn1...
             # ./mount.jkernel
             Mounted jkernel package on /dev/vn2...
             # ./mount.jroute
             Mounted jroute package on /dev/vn3...
      
     

  7. Enter recovery mode:

             # /usr/libexec/ui/recovery-mode
      

  8. Enter configuration mode and change the root authentication password:

             root> configure 
             Entering configuration mode
      
             [edit]
             root# set system root-authentication plain-text-password    
             New password:
             Retype new password:
     
     
     

  9. Commit the changes, and exit configuration mode

             [edit]
             root # commit 
             commit complete
      
             [edit]
             root@router# exit 
             Exiting configuration mode
      
             root@router> exit 
      

  10. Exit recovery mode and enter ‘y’ when prompted to reboot the system:

              Reboot the system? [y/n] y
              Terminated
      

      The system now reboots and changes made to root authentication are activated.

• For routers running Junos 4.X.
  1. Obtain console access
  2. Power off the system and boot it up in single user mode. This is done by typing “-s” at the boot: prompt.

      Example:

           >> BOOT @ 0x10000: 639/64512 k of memory, serial/dual console
           Boot default: 0:wd(0,a)kernel
           Usage: bios_drive:interface(unit,partition)kernel_name options
               interface    fd, wd or sd
               unit         0, 1, ...
               partition    a, c, ...
               kernel_name  name of kernel, or ? for list of files in root directory
               options      -c (userconfig) -s (single user) -v (verbose)
                           -D (dual consoles) -h (alternate console) -P (probe kbd)
     
     
           boot: -s    <====== Type "-s"
     
     
     

  3. Next, the system will run the normal bootup process. When prompted for pathname enter:

          /usr/libexec/ui/recovery-mode

     This will run a script for password recovery.

           Enter pathname of shell or RETURN for sh: /usr/libexec/ui/recovery-mode  
     
     

  4. The system will finish booting up and display the  root> prompt.

           ...
           ...
           NOTE: the system
           Starting CLI ... 
           root> 
     
     
     

  5. Enter configuration mode and edit or delete the root authentication password.

            root> configure 
            Entering configuration mode
     
            [edit]
            root# delete system root-authentication 
     
            [edit]
            root# commit and-quit 
            commit complete
            Exiting configuration mode
     
     

  6. Finally, reboot the system.

           root@congo3> request system reboot 
           Reboot the system ? [yes,no] (no) yes