Examine Figure 1-3. This is a slightly more advanced example of a LAN.

Understanding Local Area Networking | 5 In Figure 1-3, we have added more central connecting devices. Instead of connecting hundreds of devices to a single central connecting device, we can break up the network in a hierarchical fashion. For example, on the left side of the figure, there are two PCs and one server connected to a hub. Let’s say that these represent 24 computers, and that each other group of computers connected to a hub also represents 24 computers. Instead of connecting all of the computers to a single central connecting device, which might not be able to physically support all of these hosts, we have connected the groups of 24 hosts to their own hub. Then, the hubs are all daisy-chained to a switch at the top of the figure. The switch will most likely be a powerful and expensive device, in order to support all of the computers that ultimately connect to it. You can regard the individual hubs as devices that allow connectivity for single departments in a company, or perhaps for individual classrooms in a school. The master switch at the top of the hierarchical tree connects everything together. However, it also acts as a single point of failure, which we will address later in this book. As you can guess, this type of network architecture is the kind required to accomplish the goals laid out in the scenario in the beginning of the lesson. A network adapter, also known as a network interface card or NIC, is the device that enables you to send and receive data to and from your computer. This adapter might be integrated into the motherboard or act as a separate device that connects to a PCI slot, or perhaps a PC card slot or USB port. An adapter can connect to the network by cable wired or by air wireless. It has its own basic CPU to process transmitted data, as well as a ROM chip to store information about itself. Network adapters also have a software component known as a driver, which defines how the card will interact with the operating system; this usually includes a properties page that can be accessed in the operating system, thereby enabling the user to configure the adapter as he or she sees fit. VIEW A NETWORK ADAPTER GET READY. To view a network adapter, perform these steps: 1. Examine Figure 1-4. This shows a typical network adapter. Figure 1-4 A typical network adapter 6 | Lesson 1 This particular network adapter is a PCI card, but again, network adapters come in many forms. However, notice the port on the card. This is known as an RJ45 port or an 8P8C, and it is where the RJ45 plug at the end of the network cable connects. This is the most common type of network adapter port, allowing the adapter to connect to most of today’s wired networks.

2. Look for the network adapter on your computer. If the computer only uses a wireless

network adapter, look for an antenna on the card. Laptops have an internal antenna, but you can usually know whether you are connected wirelessly by looking at the wireless LED.

3. Examine Figure 1-5. This is a typical patch cable that connects to an RJ45 port.

Figure 1-5 A typical patch cable This type of cable is known as twisted pair. It has an RJ45 plug on its end, which is molded so it can only connect one way to the RJ45 port. It also has a tab that locks it in place. Although the RJ45 plug looks very similar to a telephone cable’s RJ11 plug, the RJ45 plug is slightly larger. Another difference is that the phone plug will usually have four wires, whereas the RJ45 plug will have eight. 4. Identify the cable that connects your computer to the network. Disconnect the cable first, finish any downloads from the Internet if you have any in progress and view the connector. If you are connected wirelessly, attempt to identify the cables that are connected to a hub, switch, or router.

5. Now, access the operating system and look at the properties of the network adapter.

As an example, we will use a Windows 7 client computer with an Intel network adapter. Older versions of Windows have almost identical window and dialog box names, and the navigation to those windows is similar as well.

a. Click Start.

b. Right click Computer.

Understanding Local Area Networking | 7 c. Select Manage. This should display the Computer Management console window. d. Click Device Manager. e. Click the plus ⫹ sign to expand the Network adapters category, as shown in Figure 1-6. Figure 1-6 Device Manager with the Network adapters category expanded

f. Right-click the network adapter and select Properties. This will display a window

similar to Figure 1-7. Figure 1-7 Properties window of an Intel network adapter