I'd like to start this subsection by talking about the Spanning Tree Protocol (STP). Look at the simple topology shown in the following diagram. In this topology, I have two switches connected to each other with two links:
Figure 6.8: Switches connected with redundancy
This is a common practice and offers redundancy. Should one of the links fail, the other is there to allow communication to take place between the two switches. I'd like you to think for a moment about what happens if PC 01 sends some data to Switch 1 and Switch 1 either doesn't know the outbound interface or it's addressed to a broadcast/multicast MAC ...
