State of the RDP Finite State Machine. Possible values:
- isolated: the node is isolated.
- discovery: the node is not isolated and is in the process of
gathering Appian ring information.
- master: the Appian ring information has been gathered and this
node plays the role of master in the Ring Discovery Protocol
(node with lowest Appian DCC MAC in the ring).
- pleb: the Appian ring information has been gathered and this
node does not play the role of master in the Ring Discovery
Protocol (there is a node with a lower Appian DCC MAC in the
ring).