An administrator is configuring a High Availability (HA) pair of ION 3000 devices at a...

Comprehensive and Detailed Explanation

In a Prisma SD-WAN High Availability (HA) deployment, theHA Control Interfaceis the critical lifeline used to synchronize state, heartbeats, and flow information between the Active and Standby ION devices.

The strict requirement for this connection is that it must beLayer 2 adjacent.

Best Practice:A direct physical cable connection between the designated HA ports of the two devices (e.g., Port 2 on Device A to Port 2 on Device B).

Alternative:Connectivity through a switch on a dedicated, isolated VLAN is supported, provided the devices are in the same broadcast domain and subnet.

Routing (Layer 3) isnot supportedfor the HA Control link because the keepalive mechanism relies on low-latency, multicast/broadcast-level adjacency to detect failures instantly (sub-second failover). If the HA link were routed (Option A), network latency or router convergence issues could cause "Split-Brain" scenarios where both devices assume the Active role, leading to IP conflicts and traffic loops. Option C is incorrect because the Controller is too slow to manage real-time failover; the decision must be local.