The STP-enabled ports have different states, as follows:

• Blocking state: This is the initial state of each port when the switch is powered on. Ports that are in the blocking state will not forward any traffic. They only listen to the traffic and continue to be in the blocking state. If they receive any topology change notification frames, then they would convert into the listening state till the change gets stabilized and these port would be ready to take a new state, if required.
• Listening state: Ports in this state do not forward any traffic. They only listen to the traffic. This is the next immediate state of the blocking state. This is also the first step of start-frame forwarding. The time it takes for the transition is 15 seconds by default.
• Learning state: Ports in this state start learning the addresses while listening to the traffic of the connected device in that segment. The default time is 15 seconds.
• Forwarding state: In this state, the ports would forward and will continue listening to the traffic, that is, learning the addresses.
• Disabled ports: These ports neither listen nor forward any traffic.