What is the function of the command set av-failopen while using proxy-based inspection?

The function of the command set av-failopen in the context of proxy-based inspection is to determine the behavior of the system when there is a failure during antivirus scanning. When proxy-based inspection is employed, the system performs deep packet inspection to scan content for malicious threats. If, for any reason, the antivirus service encounters a failure—such as being unable to connect to the antivirus database or due to a temporary service issue—this command allows you to configure how the system should handle such situations.

Specifically, the fail-open option allows traffic to pass through even if the antivirus scanning fails. This can be particularly important in environments where maintaining user access and operational continuity is critical. Conversely, if fail-close were configured, the traffic would be blocked until the issue is resolved, potentially leading to business disruption.

This command is essential for ensuring that organizations can balance security with usability, allowing for continuous operation even in the face of potential scanning failures. The other options do not relate to the operational behavior during antivirus scanning failures; hence their relevance as alternatives is limited.