What is the default interface used as the Heartbeat Backup Link for High Availability (HA)?

In the context of SonicWall devices configured for High Availability (HA), the Heartbeat Backup Link is crucial for ensuring seamless failover between primary and secondary units. The default interface designated for the Heartbeat Backup Link is X3. This interface is specifically allocated for the purpose of monitoring the health and status of the primary device, enabling quick failover in case of a failure.

The choice of X3 as the default for the Heartbeat Backup Link is part of SonicWall's design to ensure optimal performance and reliability in a redundant setup. It allows the firewall appliances to communicate with each other to exchange operational states, maintaining synchronization of configurations and session information.

The other interfaces, such as X1, X2, and X4, typically serve different primary functions (like LAN, WAN, or DMZ connections) and are not designated specifically for Heartbeat communication in HA setups. This specialization in function ensures that the Heartbeat traffic is isolated, minimizing the impact on throughput and providing a more stable environment for failover processes.