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E. Single/Dual Unit Configurations
1. Single Unit Configuration
The topology in standalone-mode looks like this:
2. High Availability (HA) Configuration
The High Availability 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 your network. One
machine serves as the active balancer, the second one remains in a standby, idle state, always prepared to
take over the activities from the active server. This two-machine cluster appears both to the Internet side and
to the server farm side as a single logical unit.
Note: If you are running a High Availability (HA) cluster, which consists of two interconnected LoadMaster
nodes, each network interface has an individual IP address and a shared (sometimes called floating) IP
address. The shared IP address is identical for both LoadMaster nodes, but active only for one LoadMaster at
any one time.
During normal operation each node is periodically sending health check messages over the two connections to
cross check the operability of the peer machine. In the unlikely event that a LoadMaster should fail, the
standby machine will become active and take over the task of balancing.
