The ADC can be used as a single stand-alone device, and it will work perfectly well doing that. However, when one considers that the purpose of the ADC is to load balance sets of servers, the need to cluster the ADC itself becomes apparent. The ADC’s easily navigable UI design makes the configuration of the clustering system straightforward.
The System > Clustering page is where you will configure the high availability of your ADC appliances. This section is organized into several sections.
Important Note
There is no requirement for a dedicated cable between the ADC pair to maintain a high availability heartbeat.
The heartbeat takes place on the same network as the Virtual Service that requires high availability to be put in place.
There is no stateful fail-over between the ADC appliances.
When high availability is enabled on two or more ADC’s, each box will broadcast via UDP the Virtual Services it is configured to provide.
High availability fail-over uses unicast messaging and Gratuitous ARP to inform the new Active load balancer switches.
