Cisco 9000 – Upgrading Software

Upgrading Cisco Catalyst 9000 (Cat9K) switches is a crucial process for network maintenance and efficiency. This post provides detailed methods for upgrading these switches, focusing on both the traditional Bundle Mode and the newer, recommended Install Mode.

Requirements and Components

This post applies to Catalyst models: C9200, C9300, C9400, C9500, and C9600. While the post is based on specific hardware and software versions, the core concepts are broadly applicable.

Background Information

The procedures here stem from lab-tested methodologies, starting from a default configuration. Understanding the impact of any command on a live network is essential before proceeding.

Install Modes Overview

Bundle Mode
In Bundle Mode, switches run in a traditional Cisco IOS style, booting from a .bin file. This method involves setting the boot statement to point to the desired .bin file, ensuring that the switch loads the correct version upon reboot.
Install Mode
Install Mode, the recommended approach involves breaking down the .bin file into smaller .pkg files. This Mode allows for faster booting and better memory utilization. The upgrade process in Install Mode is more streamlined, with the switch automatically pointing to the necessary .pkg files for booting.

Upgrade Methods

Autoupgrade is useful when the active supervisor is in Install Mode. It automates the upgrade of the standby supervisor, ensuring version consistency across the system.
Install Mode Commands
In Install Mode, specific commands are used for the upgrade process, including install add, install activate, and install commit. Each command plays a vital role in ensuring a smooth upgrade.
Upgrade Commands
  • install add: Copies new .bin file and extracts .pkg files
  • install activate: Points to new .pkg files and reloads switch
  • install commit: Stops rollback timer and completes upgrade
Bundle Mode
Bundle Mode is a more traditional upgrade method that involves changing the boot statement to point to the new .bin file.

Summary and Best Practices

To transition to Install Mode, update the boot statement to packages.conf and use the install commands for a seamless upgrade process. If space issues arise during the upgrade, refer to the Cleanup section of this document.

Additional Tips

  • Install Abort: If issues arise post-activation but pre-commit, the install abort command allows reverting to the previous version.
  • Prompt Level: Adjust the prompt level to streamline the upgrade process.
  • Auto Upgrade Timer: Monitor and adjust the upgrade timer as necessary.

Specific Methods

  • Legacy Method: For models 9500 and 9300, although not recommended, the request platform commands are available.
  • Stackwise Virtual Upgrade Method: For dual-supervisor setups, the upgrade process involves specific steps to ensure minimal downtime.
  • Roll Back in Install Mode: Rolling back to a previous version is possible if needed, with multiple rollback points available.
  • ISSU Upgrade Method: For dual-supervisor systems, ISSU provides a way to upgrade with minimal service interruption.
  • ReloadFast: A feature that reduces downtime during upgrades, especially effective in single-switch scenarios.
  • Cleanup: Post-upgrade, removing inactive files is advisable to free up space.


  • V-Mismatch: Address version mismatches between switches in a stack.
  • Recovery from Rommon: Steps to recover a switch stuck in rommon Mode.