This document describes a set of state machines for EAP peer, EAP standalone authenticator (non-pass-through), EAP backend authenticator (for use on Authentication, Authorization and Accounting (AAA) servers), and EAP full authenticator (for both local and pass-through). This set of state machines shows how EAP can be implemented to support deployment in either a peer/authenticator or peer/authenticator/AAA Server environment. The peer and standalone authenticator machines are illustrative of how the EAP protocol defined in [RFC3748] may be implemented. The backend and full/ pass-through authenticators illustrate how EAP/AAA protocol support defined in [RFC3579] may be implemented. Where there are differences [RFC3748]/[RFC3579] are authoritative. The state machines are based on the EAP "Switch" model. This model includes events and actions for the interaction between the EAP Switch and EAP methods. A brief description of the EAP "Switch" model is given in the Introduction section. The State Machine and associated model are informative only. Implementations may achieve the same results using different methods.