How to modify the CARP MAC Address for the LoadMaster

This article covers the instructions on how to modify or customize the CARP MAC address used in the LoadMaster High Availability (HA) configuration. 

Product: LoadMaster

Version: Any

Platform: Any

Application: Any

How can the CARP MAC address can be modified in the LoadMaster?

Nowadays, many network devices have the capability to operate in high availability mode and sometimes these devices when not carefully configured can conflict with each other due to the duplication of the CARP MAC address.

When the LoadMaster is implemented in High Availability mode (HA) a CARP MAC address is automatically generated based on the information provided during the HA configuration. 

The formula 00:00:5e:00:1+(2*IntID):HAID is used to generate the CARP MAC address. Whereby IntID = Interface ID, i.e eth0 (ID = 0), and HAID = HA Virtual ID. So, if the HA was configured using the interface eth0, the CARP MAC address of the virtual interface is 00:00:5e:00:01:XX, where the last two digits will be populated by the hexadecimal value of the HA Virtual ID.

Based on the information above, if the customer encounters that the CARP MAC address used by the LoadMaster is duplicated in the network, this can be easily fixed under the System Configuration -> HA Parameters -> HA Virtual ID (see screenshot). In short, the HA Virtual ID value must be changed so that it becomes unique in the network. Once the value has been changed the LoadMaster needs to be rebooted so that the new CARP MAC address can be fully changed.