Juniper Networks Hickory Hill Consulting Arrcus The Border Gateway Protocol, version 4 (BGP-4) finite state machine (FSM) is defined in RFC 4271. Over the years, various extensions to BGP have been authored that update the protocol's FSM. Some elements of the FSM are enumerated. Those elements are referred to across BGP extensions in their respective state machine changes, and may also be used for management purposes in things such as YANG (RFC 7950). To provide consistent naming and enumeration of these FSM elements, this document requests IANA to create and maintain registries for elements in the BGP FSM.