Installing the Software Package on a Router with Redundant Routing Engines
If the router has two Routing Engines, perform a Junos OS installation on each Routing Engine separately to avoid disrupting network operation. Install the new Junos OS Release on the backup Routing Engine while keeping the currently running software version on the master Routing Engine. After making sure that the new software version is running correctly on the backup Routing Engine, switch over to the newly installed Routing Engine to activate the new software. Finally, install the new software on the new backup Routing Engine.
![]() | Warning: If graceful routing engine switchover (GRES), or nonstop active routing (NSR) is enabled when you initiate a software installation, the software does not install properly. Make sure you issue the CLI delete chassis redundancy command when prompted. If GRES is enabled, it will be removed with the redundancy command. By default, NSR is disabled. If NSR is enabled, remove the nonstop-routing statement from the [edit routing-options] hierarchy level to disable it. |
To upgrade the router software, perform the following tasks:
Preparing the Router for the Installation
Perform the following steps before installing the software:
- Log in to the master Routing Engine’s console.
For more information on logging in to the Routing Engine through the console port, see the administration manual for your particular router.
- Enter the Junos OS CLI configuration mode:
Start the CLI from the shell prompt:
# cli
user@host>Enter configuration mode:
user@host#> configure
Entering configuration mode
[edit]
user@host#
- Disable Routing Engine redundancy:
[edit]
user@host# delete chassis redundancy - Save the configuration change on both Routing Engines:
[edit]
user@host# commit synchronize Exit out of the CLI configuration mode:
[edit]
user@host# exit
Installing Software on the Backup Routing Engine
Once the router is ready, you first install the software on the backup Routing Engine. This enables the primary Routing Engine to continue operations, minimizing the disruption to your network.
- Log in to the backup Routing Engine’s console:
For more information on logging in to the Routing Engine through the console port, see the administration manual for your particular router.
- For more information on the request system software add command, see the Junos System Basics and Services Command Reference.
Install the new software package using the request system software add command:
user@host> request system software add validate /var/tmp/jinstall-9.2R1.8–domestic-signed.tgz
Reboot the router to start the new software using the request system reboot command:
user@host> request system reboot
Reboot the system? [yes, no] (no) yesAll the software is loaded when you reboot the device. Installation can take between 5 and 10 minutes. The router then reboots from the boot device on which the software was just installed. When the reboot is complete, the router displays the login prompt.
Note: You must reboot the device to load the new installation of the Junos OS on the router.
To abort the installation, do not reboot your device, instead, finish the installation and then issue the request system software delete jinstall command. This is your last chance to stop the installation.
While the software is being upgraded, the Routing Engine on which you are performing the installation is not routing traffic.
- Log in and issue the show version command to verify the version of the software installed.
- (Optional) Add the jweb package using the request system software add command. Before you can add this
package, you must first download the software as you did the installation
package. For more information on downloading the jweb package,
see Downloading Software.
The jweb installation module adds a router management graphical user interface that you can use to view and configure your router. For more information about the jweb package, see Installation Modules.
Installing Software on the Primary Routing Engine
Once the software is installed on the backup Routing Engine, you are ready to switch routing control to the backup Routing Engine and then upgrade or downgrade the primary Routing Engine software:
- Log in to the primary Routing Engine console port.
For more information on logging in to the Routing Engine through the console port, see the administration guide for your particular router.
- For more information about the request chassis routing-engine master command, see the Junos System Basics and Services Command Reference.
Transfer routing control to the backup Routing Engine:
user@host> request chassis routing-engine master switch
- Verify that the backup Routing Engine (slot 1) is the
master Routing Engine:
user@host> show chassis routing-engine
Routing Engine status:
Slot 0:
Current state Backup
Election priority Master (default)
Routing Engine status:
Slot 1:
Current state Master
Election priority Backup (default) - For more information about the request system software add command, see the Junos System Basics and Services Command Reference.
Install the new software package using the request system software add command:
user@host> request system software add validate /var/tmp/jinstall-9.2R1.8–domestic-signed.tgz
Reboot the Routing Engine using the request system reboot command:
user@host> request system reboot
Reboot the system? [yes, no] (no) yesThe software is loaded when you reboot the system. Installation can take between 5 and 10 minutes. The router then reboots from the boot device on which the software was just installed. When the reboot is complete, the router displays the login prompt.
Note: You must reboot to load the new installation of the Junos OS on the router.
To abort the installation, do not reboot your system; instead, finish the installation and then issue the request system software delete jinstall command. This is your last chance to stop the installation.
While the software is being upgraded, the Routing Engine on which you are performing the installation does not route traffic.
- Log in and issue the show version command to verify the version of the software installed.
- (Optional) Add the jweb package using the request system software add command. Before you can add this
package, you must first download the software as you did the installation
package. For more information on downloading the jweb package,
see Downloading Software.
The jweb installation module adds a router management graphical user interface that you can use to view and configure your router. For more information about the jweb package, see Installation Modules.
- For more information about the request chassis routing-engine master command, see the Junos System Basics and Services Command Reference.
Transfer routing control back to the master Routing Engine:
user@host> request chassis routing-engine master switch
- Verify the master Routing Engine (slot 0) is indeed the
master Routing Engine:
user@host> show chassis routing-engine
Routing Engine status:
Slot 0:
Current state Master
Election priority Master (default)
outing Engine status:
Slot 1:
Current state Backup
Election priority Backup (default)
Finalizing the Installation
Once the software is installed on both Routing Engines, you return the router back to its original configuration and back up the new installation.
- Restore the configuration that existed before you deleted
it at the start of this procedure:{backup}user@host-re0> configure [edit]user@host-re0# rollback 1
- Save the configuration change on both Routing Engines:[edit]user@host-re0> commit synchronize and-quit
- After you have installed the new software and are satisfied
that it is successfully running, issue the request system snapshot command to back up the new software on both master and backup Routing
Engines:{master}user@host-re0> request system snapshot {master}user@host-re0> request routing-engine login other routing-engine{backup}user@host-re1> request system snapshot{backup}
The root file system is backed up to /altroot, and /config is backed up to /altconfig. The root and /config file systems are on the router’s CompactFlash card, and the /altroot and /altconfig file systems are on the router’s hard disk.
For more information on the request routing-engine login command, see the Junos System Basics and Services Command Reference.

Note: After you issue the request system snapshot command, you cannot return to the previous version of the software because the running copy and backup copy of the software are identical.

