The HA Virtual ID can be found in the LoadMaster Web User Interface (WUI) by going to System Configuration > HA Parameters
The HA Virtual ID is a setting used for HA configuration. It is a unique value that is set on both HA-units. The setting is used if you have more than one pair in a HA configuration. Any other HA units will have to be configured with a different virtual ID number to distinguish between the different pairs. On each of the HA units, by default, the HA virtual ID is assigned to the last octet of the shared IP. If for some reason it's not then it's recommended to change this value to a random value between 11 and 255.