The High Availability (HA) feature of the LoadMaster guarantees the availability of your server farm. HA is achieved by a hot-standby, failover mechanism. Two identical LoadMaster units are integrated into the network as a cluster. One machine serves as the active LoadMaster and the second one remains in a standby, idle state - always prepared to take over the activities from the active server. This cluster appears as a single logical unit to the Internet side and to the server farm side connections.
With an HA cluster, each network interface has an individual IP address and one shared IP address which is shared with the partner unit. The shared IP address is identical for both LoadMaster appliances, though it is associated with only the active LoadMaster at any given time.
Note: If the LoadMaster is set as the default gateway of the servers, remember to use the shared address of the HA pair since this address will always be available.
During normal operation each node periodically sends health check messages over the eth0 connection to verify the availability of the peer appliance. In the event that the active LoadMaster should fail, the standby appliance will become active and take over the task of balancing.
For more information and instructions on how to configure HA, refer to the HA Feature Description document.