Network rookies leave spanning tree at defaults. The root bridge ends up as some switch in a closet. A new switch is added to the network, and sometimes traffic goes wonky for a while. Spanning tree gets blamed as if it’s a teenager with an attitude problem. Wrong. Spanning tree just needs to be managed, and then it behaves predictably. It all starts by rigging the election to make the root bridge the switch you want it to be.
Watch the video over here.