Related Topics
Active/Passive Cluster ID and the Virtual MAC Address
An active/passive FireCluster uses a virtual MAC address, calculated based on the Cluster ID and the interface numbers. If you configure more than one active/passive FireCluster on the same subnet, it is important to know how to set the Cluster ID to avoid a possible virtual MAC address conflict.
In Fireware v11.11.2 and higher, the default Cluster ID is 50.
How the Virtual MAC Address is Calculated
The virtual MAC addresses for interfaces on an active/passive FireCluster start with 00:00:5E:00:01. The sixth octet of the MAC address is set to a value that is the hexadecimal equivalent of the interface number plus the Cluster ID.
For example, for a FireCluster with the Cluster ID set to 50, the virtual MAC addresses are:
Interface 0: 00:00:5E:00:01:32
Interface 1: 00:00:5E:00:01:33
Interface 2: 00:00:5E:00:01:34
If you add a second FireCluster to the same subnet, you must make sure to set the Cluster ID to a number that is different enough from the Cluster ID of the first FireCluster to avoid a virtual MAC address conflict. For example, if the first FireCluster has 5 interfaces, you must set the Cluster ID of the second FireCluster at least 5 higher than the Cluster ID for the first FireCluster.
For example, if the second FireCluster has the Cluster ID set to 56, the virtual MAC addresses are:
Interface 0: 00:00:5E:00:01:38
Interface 1: 00:00:5E:00:01:39
Interface 2: 00:00:5E:00:01:40
It is also possible that the FireCluster virtual MAC addresses can conflict with HSRP and VRRP configured devices on your network.