How to view Spanning-Tree Protocol, Manually set Root Bridge
In this video we view STP go through various states. We also manually set Root Bridge by assigning the lowest Port Priority number, this must be set up on the interface. One thing to remember is (STP Bridg-ID)Switch Interface with the lowest Priority number will become root. If equal priority number then the Switch with the lowest MAC address value wins.
This video does not cover all the rules of Spanning-Tree, so please research the different STP Port States, Root Port Election, STP Cost, Non-Root Port Election, and Port Role Rules. Other Features are STP Portfast, PVST+, STP BPDU Guard, also the latest Rapid Spanning Tree- 802.1W.
STP-Prevents Layer 2 loops-which prevents broadcast storms. Enabled by default.
STOPPING A BROADCAST STORM- textbook answer: begin physically disconnecting trunk links one at a time until activity lights on the switches begin to settle down.