A network operator receives a critical SITE_CONNECTIVITY_DOWN alarm for a branch site in the Prisma...

Comprehensive and Detailed Explanation

TheSITE_CONNECTIVITY_DOWNalarm is a high-severity alert indicating a total loss of overlay connectivity for a site.

It doesnottrigger if justonecircuit fails (Option B), provided that other circuits are still up and maintaining VPNs. A single link failure would typically trigger a "Link Down" or "VPN Down" alarm, but theSiteconnectivity would remain "Up" (degraded).

It does not simply mean the device rebooted (Option A), although a reboot would cause it temporarily; the alarm specifically tracks the state of the VPN fabric.

The SITE_CONNECTIVITY_DOWN alarm specifically generates when all Secure Fabric Links (VPN tunnels) on the device are in the "Down" state. This means the branch is completely isolated from the rest of the SD-WAN network (Data Centers and other branches), even if the device itself might still be powered on and reachable via the controller (management plane). It signifies a "Blackout" of the data plane for that location.