Migration, Upgrade, and Downgrade Instructions
This section contains the procedure to upgrade Junos OS, and the upgrade and downgrade policies for Junos OS for NFX250 devices. Upgrading or downgrading Junos OS might take several hours, depending on the size and configuration of the network.
Upgrade and Downgrade Support Policy for Junos OS Releases
Support for upgrades and downgrades that span more than three Junos OS releases at a time is not provided, except for releases that are designated as Extended End-of-Life (EEOL) releases. EEOL releases provide direct upgrade and downgrade paths—you can upgrade directly from one EEOL release to the next EEOL release even though EEOL releases generally occur in increments beyond three releases.
To upgrade or downgrade from a non-EEOL release to a release more than three releases before or after, first upgrade to the next EEOL release and then upgrade or downgrade from that EEOL release to your target release.
For more information on EEOL releases and to review a list of EEOL releases, see https://www.juniper.net/support/eol/junos.html.
Basic Procedure for Upgrading to Release 15.1X53-D496
When upgrading or downgrading Junos OS, use the jinstall package. For information about the contents of the jinstall package and details of the installation process, see the Installation and Upgrade Guide. Use other packages, such as the jbundle package, only when so instructed by a Juniper Networks support representative.
The installation process rebuilds the file system and completely reinstalls Junos OS. Configuration information from the previous software installation is retained, but the contents of log files might be erased. Stored files on the device, such as configuration templates and shell scripts (the only exceptions are the juniper.conf and ssh files), might be removed. To preserve the stored files, copy them to another system before upgrading or downgrading the device. For more information, see the Junos OS Administration Library.
We recommend that you upgrade all software packages out of band using the console because in-band connections are lost during the upgrade process.
To download and install Junos OS Release 15.1X53-D496:
- Using a Web browser, navigate to the All Junos Platforms software download URL on the Juniper Networks webpage:
- Select the name of the Junos OS platform for the software that you want to download.
- Select the Software tab.
- Select the release number (the number of the software version that you want to download) from the Version drop-down list to the right of the Download Software page.
- In the Install Package section of the Software tab, select the software package for the release.
- Log in to the Juniper Networks authentication system using the username (generally your e-mail address) and password supplied by Juniper Networks representatives.
- Review and accept the End User License Agreement.
- Download the software to a local host.
- Copy the software to the device or to your internal software distribution site.
- Install the new package on the device.