What is the correct order of the BGP FSM states?

a. Idle, Active, Connect, Opensent, Openconfirm, Established
b. Idle, Connect, Active, Opensent, Openconfirm, Established
c. Idle, Connect, Opensent, Active, Openconfirm, Established
d. Idle, Connect, Opensent, Active, Openconfirm, Established

b. Idle, Connect, Active, Opensent, Openconfirm, Established
Explanation: Idle state is the initial state where the resources are initialized and a BGP router is initiating a TCP connection with its BGP peer. Connect state is the next state after the initialization is done. A BGP router waits for a successful TCP connection with its BGP peer. Active state is when the TCP connection between BGP peers cannot be established. The term active is misleading in this case because it does not imply a positive or successful operation. While in this state, it continues to try to establish a TCP connection with its peer. If it is still unsuccessful, the state is reset to idle. Opensent state indicates a successful TCP connection between the BGP peers. At this point, the BGP peers exchange the open message to establish the peering and check the validity of the peering setup information. Openconfirm state is the state where the BGP router is waiting for a BGP keepalive message from its peer. The keepalive message is the indicator the open message is accepted by its peer. Established state is the final state indicating the BGP peering is established and the routing can be exchanged.