Upgrading firmware on Sonicwall email security appliance

This is the procedure we follow to upgrade the firmware on our Sonicwall 3300 email security appliance:

- Download new firmware and check MD5 checksum.

- Backup appliance settings.

- SSH to appliance using Putty and log in as "snwlcli".

- When prompted enter the appliance's admin's username and password.

- Run "stop appservices". It'll take a minute.

- Run "start tomcat".

- Wait for GUI to restart and then log in again.

- Update the firmware through "Advanced" under "System". Updating the firmware can take 10 minutes or more depending how how many users and spam you have on the appliance.

Not following this can lead to issues. Unfortunately, Sonicwall doesn't make it easy to find the correct procedure on their site.