Which process is critical before updating the Sophos XG Firewall software?

Backing up existing settings is a crucial step before updating the Sophos XG Firewall software because it ensures that you have a safe copy of your current configuration and policies. In the event that the update introduces issues, or if you encounter any unforeseen complications during the update process, having a backup allows you to restore your firewall to its previous operational state quickly and efficiently. This practice minimizes downtime and ensures continuity of service.

While running a hardware diagnostic can be useful for assessing the health of the hardware before an update, it does not directly relate to ensuring that your settings and configurations are preserved. Configuring VPN connections and performing the initial setup are more about establishing functionality, rather than protecting your current settings and configurations during an update process. Therefore, backing up existing settings stands out as the most critical preparatory step.