Best practices, recommendations, and precautions

Best practices for software updates


There is a slight change in the versioning system.

Software updates that contain significant new features and enhancements may be designated by an increment to both the major and minor release version numbers. That is, K.15.01.0031 represents a major update to software version(s) K.14.xx, and K.14.xx represents a major update to K.13.xx, and so forth. In addition, a future version (such as K.15.02.xxxx) may represent a minor release to version K.15.01.xxxx, but may still contain significant changes. To mitigate against potential migration issues when performing such updates, this section documents best practices for updating the switch, including contingency procedures for rolling back to previous software versions and saved configurations.

Recommendations and precautions for software updates

Before you update the switch software to a new version:

  • We strongly recommend that you save a copy of your config file to an external location.

  • We advise against rolling back (going from a newer software version to an older software version) without copying a backup config file to the device.

If you do choose to downgrade software using your existing config file, unpredictable changes in the config file and switch behavior may occur. If booting a K.15.01.0031 or later config file into a K.14.xx or earlier versions of software, the following commands may be removed from your config file:

  • Any commands that are present in K.15.01.0031 (or later) but are not present in earlier versions of software

  • logging

  • snmp-server

  • mirror-session

  • auto-tftp

  • filter source-port

  • fault-finder

  • interface loopback

After following these steps, you end up with the following results:

  • Primary image will hold the new software image you want to install

  • Secondary image will hold the image you are currently running

  • Primary image will boot with Config1 (config file corresponding to new software version)

  • Secondary image will boot with Config2* (config file corresponding to previous software version)

* The current config file must be copied to Config2, or you will be unable to revert if the need arises.


You might opt to use a different methodology in which the new software will be installed as the secondary and not the primary image, in which case you would use the commands boot system flash secondary, and/or boot set-default flash secondary to change the location of the default boot. However, since you will still need to take precautions to allow you to revert to your previous configuration. We strongly recommend that you follow the methods that are proposed in our update process. This will ensure that you can use our proposed rollback procedures if the need arise.