When a blocked port needs to become forwarding, it passes through listening and learning first. In listening, the port participates in STP by sending and receiving BPDUs. It does not learn MAC addresses yet. After the forward delay timer expires (default seconds), it moves to learning. In learning, it starts populating the MAC table but still does not forward user traffic. After another forward delay, it reaches forwarding. This -second delay prevents temporary loops.
##### ###### ##### ### # # ### # # ###### ## ## ## ## ## ## ## # # # # # ## ##### #### ##### # # # # # # # #### ## # ## ## ## ## # # # # # ## ## # ###### ## ### # ### # ######
$ curl repovive.com/roadmaps/network-design/spanning-tree-and-link-aggregation/listening-and-learning-states
░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░████████████████████████████████████████████████████████████████████████████████████████████████████████████