Installing a Different JUNOS Software Version on a Router

This chapter describes how to install a different JUNOS software version on a routing platform—for example; to upgrade from JUNOS 7.6 to JUNOS 8.0.

For information about upgrading from JUNOS 5.x or later to 7.x or later, see the Knowledge Base Asset # 24602 on the Juniper Networks Support Web site at http://www.juniper.net/support.

NOTE: Downgrading by more than three releases may not be straightforward. In particular, if your routing platform is running JUNOS Release 7.5, you can downgrade directly to Release 7.2, but you cannot downgrade directly to Release 7.1. As a workaround, you can first downgrade to Release 7.2 and then downgrade to Release 7.1. See the release notes for each software release for details.

For information about JUNOS software media and packages, see JUNOS Software Media and Packages.

This chapter discusses the following topics:

• Confirming that Current Configuration Is Compatible with the Candidate Software
• Verifying PIC Combinations
• Determining Which JUNOS Software Version Is Running
• Upgrading All Software Packages
• Upgrading Individual Software Packages
• Installing the JUNOS Software on Routers with Redundant Routing Engines