Loop problems caused by: a broadcast storm, repeating frame multi-frame, the switch MAC address table instability
Spanning Tree Protocol can automatically find and eliminate redundant network topology loops.
STP Related concepts: bridge ID, port ID, root bridge, non-root bridge, root port, designated port, blocked ports, root path cost, Forwording Blocking BPDU
ID bridge (bridge ID of the switch becomes the root bridge):
(1) The bridge priority value range: 0 to 65535
(2) Default: 32768 (0x8000)
Priority, lowest priority bridge (3) first determines the bridge becomes the root bridge
(4) If the priority of the bridge the same, the bridge MAC address with the MAC address will be the switch or bridge with bridge
Port number ID (participation in elections root port):
(1) The port priority is a number from 0 to 255, the default value is 1289 (0x80)
The smaller (2) the port priority value, the higher the priority
(3) if the port of the same priority, the lower the number, the higher the priority