Understanding Layer 2 networks

You may be familiar with the term Autobahn. The Autobahn is a network of federal highways in Germany that is known for its reputation for high speeds and efficient transportation. It is an essential part of Germany’s transportation infrastructure, connecting various cities and regions across the country. But how does one get onto an Autobahn from home, office, or anywhere? You need to get into a service lane or a secondary road and follow signs to get onto the Autobahn highway. L2s are your service roads to L1, the Autobahn.

The following figure illustrates a comparison of the L1 and L2 networks with the Autobahn.

Figure 15.1 – Autobahn L1 and L2 example

Although it's not shown in the figure, the Autobahn also connects back to the service roads, which is also especially important. This ensures smooth entry and exit onto and off the Autobahn and the service roads. Now, let us see how this is related...