STP was introduced at the switch, it's a port from learning state to forwarding state to undergo a forwarding delay, the default is the forwarding delay s
In the STP protocol, set all the switches are configured the same priority, the MAC address of switch 1 00-e0- fc-00-00-40, the MAC address of the switch 2 00-e0-fc-00-00 -10, the MAC address of the switch 3 00-e0-fc- 00-00-20, the MAC address of the switch 4 is 00-e0-fc-00-00- 80, is the root switch should be
In order to calculate the spanning tree, need to exchange information between devices and parameters, and parameters such information is encapsulated in, passing between devices.