Juniper Networks J-Series - Manual (Page 207)

Downgrading the Software
When you upgrade the JUNOS software, the router creates a backup image of the
software that was previously installed, as well as installs the requested software
upgrade.
To downgrade the software, you can use the backup image of the software that was
previously installed, which is saved on the router. If you revert to the previous image,
this backup image is used, and the image of the running software is deleted. You
can downgrade to only the software release that was installed on the router before
the current release with this method.
Use the procedures as described in “Installing Software Upgrades with the J-Web
Interface” on page 182 and “Installing Software Upgrades with the CLI” on page 184
and specify an older software image as the source image to be upgraded.
Downgrade the JUNOS software on the Services Router with either the J-Web interface
or the CLI.
This section contains the following topics:
■ Downgrading the Software with the J-Web Interface on page 185
■ Downgrading the Software with the CLI on page 185
Downgrading the Software with the J-Web Interface
You can downgrade the software from the J-Web interface. For the changes to take
effect, you must reboot the router.
To downgrade software:
1. In the J-Web interface, select Manage>Software>Downgrade. The image of
the previous software version (if any) is displayed on this page.
NOTE: After you perform this operation, you cannot undo it.
2. Select Downgrade to downgrade to the previous version of the software or Cancel
to cancel the downgrade process.
3. When the downgrade process is complete, for the new software to take effect,
select Manage>Reboot from the J-Web interface to reboot the router.
After you downgrade the software, the previous release is loaded, and you cannot
reload the running version of software again. To downgrade to an earlier version of
software, follow the procedure for upgrading, using the JUNOS software image labeled
with the appropriate release.
Downgrading the Software with the CLI
You can revert to the previous version of software using the request system software
rollback command in the CLI. For the changes to take effect, you must reboot the
Downgrading the Software ■ 185
Chapter 10: Performing Software Upgrades and Reboots