To use the HA feature, you require a dedicated cluster link for firewall-to-firewall communication. This link is essential to make the HA feature work properly. Use a redundant interface, e. g. a bond interface that is provided through link aggregation.
Important: The following interfaces cannot be used as cluster links: VLAN, WLAN, PPP, Bridge interface
Use a switch to separate the cluster link to smoothly monitor the master node and the slave node through SNMP.
