Networking Bible

Chapter 7. The Network Interface

IN THIS CHAPTER

• Physical and logical interfaces

• Physical and logical interface addresses

• The binding and provider order's effect on performance

• Multihomed isolation and routing

• Network card features

An interface occurs where two different media or substances form a boundary. Each of the connections in a network is a network interface, and that interface represents the boundary between the physical transport layers that transfer communication and the layers that prepare data for use with applications. A network interface is addressable, that is, a signal can be sent over physical media meant for that specific interface.

In most networking books, the concept of a network interface isn't clearly defined and is discussed only in relation to various topics. However, I begin this chapter by defining a network interface. Network connections and their properties are important concepts that apply to networks of all types and are also covered in this chapter. From an outside perspective, the network interface is the only representation of a networked device that an outside observer sees.

What Is a Network Interface?

Let's begin by defining what a network interface is. A network interface is the boundary between two different types of networking media. Network interface is a loose term that can be applied to any of the following:

• The point where two different networks meet, particularly in a topological or architectural diagram

• A network card, an ASIC (Application Specific ...