When creating a Cloud Edge HA group, one interface on each HA peer is designated as the heartbeat interface. This interface is chosen during HA group creation.
The heartbeat interface must be an L3 interface.
The heartbeat interface must use the same interface on each gateway (for example: LAN2-to-LAN2 or LAN3-to-LAN3).
The two heartbeat interfaces must be connected directly to each other (not through a switch).
Heartbeat interfaces cannot be used for other purposes, such as LAN traffic interfaces.
You must configure IPv4 addresses and netmasks for the heartbeat interfaces and the IPv4 addresses must be on the same subnet.
After an interface has been selected as a heartbeat interface, you cannot change the configuration of that interface, including gateway IP addresses.
Because Cloud Edge uses only one interface for the HA group heartbeat, issues with the heartbeat connection might cause an condition known as the split-brain problem. Cloud Edge must be able to handle this condition.
Split-brain: A split-brain condition is the result of a cluster partition, where each side believes the other is dead, and then proceeds to take over resources as though the other side no longer owns any resources.