What is differrence between STP and RSPT ?

 RSTP has faster convergence than STP. This is because RSTP does not rely on forwarding delay timers, making it faster and more efficient. RSTP also allows for easier port transitions from discarding to forwarding states, which is beneficial in a network where switches are constantly changing roles

RSTP can be described by three port states: Discarding, Learning, and Forwarding. The Disabled, Blocking, and Listening states described by STP have been combined into the Discarding state in RSTP. The functionality is similar.

In RSTP, the Alternate port and Backup port are allowed to directly enter the forwarding state which allows the convergence time of the network to be reduced significantly. In STP, the port must wait for the network to converge (40-50 seconds) before entering the forwarding state. This is a major advantage of RSTP over STP.

 

STP	RSTP	Description
Disabled	Discarding	The port only listens for BDPUs. There is no forwarding, processing, or learning of MAC addresses.
Blocking
Listening
Learning	Learning	The port sends and receives BPDUs and also learns MAC addresses. Forwarding does not occur in this state.
Forwarding	Forwarding	The port can send and receive data, learn MAC addresses, and forward data to its destination.

RSTP Port Roles

Root Port	The port that receives Bridge Protocol Data Units (BPDUs) on the root bridge. These are messages that are exchanged between switches on the network.
Designated Port	The port selected in each local area network (LAN) segment which provides the lowest root path cost. The higher the link speed, the lower the cost value.
Alternate Port	If a port is not to be used as a designated port, it will become an alternate port. This is a backup for the root port in case of failure and is blocked during typical operation of the root port.
Backup Port	This is the backup for the designated port. If the root port fails, the backup port becomes the new designated port. The backup port is normally blocked with the designated port is operating correctly.