State transition protocol for high availability units

In a system including a first edge device managing policies of a first network, a second edge device managing policies of a second network, and a central policy server in communication with the first and second edge devices, a method for avoiding a single point of failure in the central policy server and the first and second edge devices, the method comprising:

• maintaining first class units for the central policy server and the first and second edge devices, wherein the central policy server manages the first and second edge devices from a single location;
• maintaining second class units of the central policy server and the first and second edge devices, each of the second class units acting as a backup for a corresponding first class unit, each of the second class units being initially in an inactive state;
• detecting a failure of one of the first class units;
• and
• transitioning the corresponding backup unit from the inactive state to an active state upon detection of the failure.