Remember from the last chapter that you have two connections between Switch1 and Switch2, and that the Spanning Tree Protocol (STP) allows traffic to traverse only one of those links. This prevents bridging loops but has a downside: it consumes an additional port on each switch without letting you use the bandwidth of those ports.
A port channel—also known as an EtherChannel—lets you have the best of both worlds. It allows traffic to flow simultaneously across both links while still preventing bridging loops.
As you go through this chapter, you’ll learn how to configure a port channel to achieve the configuration shown in figure 13.1.