1. The device will reboot and services will be interrupted during a software upgrade.

2. The upgrade process takes about 20 to 40 minutes and cannot be interrupted. It is recommended to do the engine upgrade by selecting the maintenance window or a time that the operation will have the least effect on the business relatively.

3. Please save the running configuration before upgrading. It is recommended to save the export configuration file.

4. Signature library upgrade and rollback can cause temporary outage for DPI services. Services based on the DPI services might also be interrupted.

5. Verify that the models supported by the upgrade package match the product models. Different models have different upgrade package files.

6. Verify the MD5 value of the upgrade packages.