Failure Scenarios

The following are some common scenarios that can trigger a failover from an Active to a Standby Edge:

• WAN link failure—When a WAN link on the Active Edge fails, a failover action is triggered. The SASE Orchestrator generates the “High Availability Going Active” event. This means that another WAN link on the Standby Edge will take over as Active because the peer’s WAN interface is down.
• LAN link failure—When a LAN link on the Active Edge fails, a failover action is triggered. The SASE Orchestrator generates the “High Availability Going Active” event. This means that another LAN link on the Standby Edge will take over as Active because the peer’s LAN interface is down.
• Edge functions not responding, or Edge crash / reboot / unresponsive—When the Active Edge crashes, reboots, or is unresponsive, the Standby Edge does not receive any heartbeat messages. The SASE Orchestrator generates the “High Availability Going Active” event and the Standby Edge takes over as Active.
  Note: HA Edges should be deployed within an isolated broadcast domain. During failover scenarios, to ensure a seamless transition of the Active role to the Standby Edge, it is crucial that the Standby Edge does not receive any incoming packets on the HA interface.