37. About Configuring PCs for Networking
For your PCs to correctly operate on your home or small office WiFi network, you must configure some settings. Because Windows networking uses certain conventions to identify computers on the network, and because IP networks such as the Internet require participating computers to use a particular address convention to access the Internet, you must check and configure several settings before a computer will be up and running on the network.
Microsoft networking for home and small office networks (and larger networks that use a network server) is called peer-to-peer networking because each computer on the network operates as a peer, meaning that it can both offer services (such as a file or printer) and access services provided by other computers on the network. The network itself is referred to as a workgroup.
Workgroup A Microsoft Windows peer-to-peer network. Each computer in a workgroup can provide and access resources.
The term peer-to-peer networking can cause some confusion. In terms of Microsoft Windows home or small office networking, a peer-to-peer network is a workgroup. The workgroup consists of multiple computers that share resources equally. They are peers. The term peer-to-peer networking is also used to describe Ad Hoc WiFi networking, in which two computers are configured to communicate directly using WiFi.
For a computer to participate in the network, it must be a member of the workgroup. Workgroups are limited to 10 computers because a peer computer running an operating system such as Windows XP can accommodate only 10 connections to a particular shared resource such as a folder or printer. You might find that, if several computers print to a printer that is shared by a particular computer in the workgroup, the computer sharing the printer becomes sluggish and runs more slowly because its processing power and memory are being taxed by "serving up" the resource to the other computers in the workgroup. I suggest that you limit your workgroups to 5 or 6 computers, particularly if everyone prints to a single printer that is provided as a shared resource by one of the workgroup computers.
Although the Windows XP operating system provides the capability to share resources on a network, it is certainly not designed to handle high network traffic or serve multiple resources to a large number of computers. Corporate and institutional networks use powerful servers with network server software to provide printing and file resources. These types of networks can accommodate a large number of users (hundreds and even thousands) because of the dedicated servers that "serve up" the network resources. Windows XP is designed as an end-user desktop environment for running local applications such as your email client, word processor, and web browser. Although Windows XP can also "serve up" resources, it is extremely limited in the number of other computers (the limit is 10 connections) to which it can serve a resource at any one time.
Each computer in the workgroup should be identified by a unique name. This name is also referred to as the NetBIOS name and can be up to 15 characters in length. The term NetBIOS is a holdover from an early Microsoft networking strategy, but unique names are still required to identify the computers in the workgroup.
Computers that participate in the workgroup must be configured for file and print sharing and must also be configured as Microsoft network clients. Both these settings are configured in the Properties dialog box for the computer's network adapter which in this case would be your WiFi network adapter. Configuring your WiFi adapter for file and print sharing is described in Add a Network Client or Service. Creating the workgroup is very straightforward because Microsoft provides a Network Setup Wizard that walks you through the steps of creating the new workgroup. We discuss the Network Setup Wizard in Run the Network Setup Wizard.
Let me summarize a couple of important points before we discuss IP addressing and why IP addresses are essential to network communication. In Chapter 5, "Installing and Configuring Wireless Adapters," I discussed how you configure your WiFi network adapter to communicate with the WiFi router on your home network. If we were not using WiFi as our network medium, Chapter 5 would have consisted of one sentence: "Connect a network cable from the computer to the router." Because we are using WiFi, the medium (wireless communication through radio signals) must be configured for network communication.
After the network medium (WiFi) is enabled on the computers and the WiFi router, computers must be configured with the appropriate network settings to allow them to share resources and also be a member of a Windows workgroup. Finally, computers on the WiFi network (the same is true for computers on a wired LAN) must be configured with a network addressing system that uniquely identifies each computer. This is where IP addressing comes in.
The TCP/IP protocol is a set of rules that dictate how computers use IP addresses to communicate on a TCP/IP network. We use IP addressing on both large and small networks (workgroups) today because it is necessary for computers to access the Internet, which is itself a huge TCP/IP network.
The TCP/IP protocol is set up by default on a computer running the Windows XP Home or Professional operating system.
Every device (both computers and WiFi routers) on your network must be assigned an IP address. The WiFi router is typically assigned its IP address automatically by your Internet service provider when you connect the WiFi router to your broadband connection device (such as your DSL router or broadband modem).
IP addresses are dotted decimal addresses that are written as four sets of decimal numbers separated by periods. For example, 220.127.116.11 is the correct format for an IP address. IP addresses are also accompanied by a subnet mask. The subnet mask helps computers determine what part of the IP address refers to the network and what part of the address refers to the actual computer that has been assigned the address. Subnet masks are also written in the dotted decimal format. For example, 255.255.0.0 would be a subnet mask that could accompany the 18.104.22.168 IP address.
IP address A dotted decimal representation of a binary address that is uniquely assigned to each computer and device running on an IP network.
There is no question that IP addressing is confusing for the home network or small office aficionado. A number of websites and many good books can expand your knowledge of the IP addressing scheme and the part that subnet masks play in IP addressing. Most networks currently use the IPv4 standard, which embraces the four-part, dotted decimal numbering system discussed and used in this chapter. A new version of IP, called IPv6, is now available and uses a different numbering system, which will only make it more difficult for home network administrators to understand how to configure IP address settings. I suggest that you allow your WiFi router to dynamically provide the IP addresses and subnet masks for the computers on your WiFi workgroup. The router is typically configured to do this right out of the box. This approach also provides additional security because your network "hides" behind the WiFi router. Only the WiFi router has a "real" IP address, which it gets from the broadband device provided by your Internet service provider.
IP (Internet Protocol) networks require that each computer has a unique IP address. This address is used to identify the computer for both the sending and receiving of data on the IP network. Because the WiFi router automatically provides the IP address for the computers on the WiFi network, you don't have to worry about configuring the computers with the IP address and the subnet mask that are required. The router does this for you using the Dynamic Host Configuration Protocol. When a computer comes online, it asks the router for an IP address and subnet mask. The router answers by providing this information to the computer.
The only time you will have to assign static IP addresses to WiFi-enabled computers is when you want the computers to communicate on an Ad Hoc network that does not use a WiFi router (see Configure Adapter for Computer-to-Computer Networking). Although letting your WiFi router dole out appropriate IP addresses and subnet masks to your workgroup computers keeps you blissfully ignorant of actually working with different IP address classes and static addressing, it certainly doesn't hurt to have a basic understanding of IP addressing and subnet masks.
The IP addressing scheme was actually developed in the 1970s when the Internet was first being created. Today, in the United States (and most of North and South America), IP addresses are "leased" by companies from the American Registry for Internet Numbers (ARIN). The company pays for a range of addresses and then uses them as public IP addresses so that the company can participate on the Internet. Your Internet service provider leases its IP addresses from ARIN and then assigns you an IP address for your high-speed Internet connection using DHCP.
The IP addressing scheme is actually divided into three different classes: Class A, B, and C. These classes were created so that companies and institutions could be assigned IP address ranges based on their size and their need (in terms of the number of addresses required).
Each IP address also has a default subnet mask. The mask is used by the computers and other devices on the network to determine which part of an IP address provides network information and which part of the address provides addressing information related to a particular computer.
The class subnets are as follows:
If you look at the subnet masks for each class, you can see that for a Class A network, the IP address's first octet is masked by the subnet mask (the 255) and so the network information found in the IP address actually consists of the first octet. In a Class B network, the first two octets are network information; in a Class C network, the first three octets are network information. With fewer octets devoted to actual IP addresses as you move from Class A to Class C, you can see why Class C networks provide fewer individual IP addresses.
Public IP addresses allow computers and other devices to connect directly to the Internet. You don't actually need to worry about public IP addresses and your connection to the Internet. This is all taken care of by your Internet service provider. Your WiFi router is dynamically assigned an IP address to communicate with your Internet service provider and the Internet. Because the WiFi router sits at a gateway between your WiFi network and the Internet (the Internet connection provided by your ISP), the IP addresses used on your local area network (including WiFi and cabled computers on the network) don't have to be actual public IP addresses. This is true because your LAN is actually "hiding behind" the WiFi router.
The IP addresses provided dynamically by the WiFi router are private IP addresses. When the IP addressing system was originally designed for the Internet, a group of addresses from the Class A, Class B, and Class C ranges were reserved for private networking. These addresses are used by the computers and other devices on your network to communicate locally. Any communication required with the Internetsuch as web browsing or sending emailis forwarded from your local network to the Internet (by your ISP) through the WiFi router.
The ranges of addresses reserved for private use are as follows:
You will find that your WiFi router will assign IP addresses to computers on the network using one of the private range of addresses; for example, my Netgear router uses the range of addresses from 192.168.1.2 to 192.168.1.51 (Class C) as the default pool for assigning IP addresses dynamically to computers on the WiFi local area network. Most WiFi routers allow you to extend or change the range if needed. To view the range of addresses, access your router's configuration and then access the screen that provides the LAN IP settings. For example, on my Netgear router, I access the LAN IP setup screen using the router's advanced settings.
It makes sense to let your WiFi router assign the IP addresses for your workgroup computers. That way, there is no chance of having a computer configured with a duplicate IP address. If two computers have the same IP address, they are both "knocked off" the network and cannot communicate. If for some reason you decide to configure static IP address (say in an Ad-Hoc situation), do not use the addresses in the pool that the WiFi router uses to dynamically assign addresses. Use a different range of addresses for your static address assignments (although in most cases you shouldn't have any static addresses).
Because the WiFi router takes care of the IP addressing for your computer, you don't need to worry about configuring computers with static addresses unless those computers will be set up in the Ad-Hoc mode. You can use any IP addresses from the private network ranges. Just make sure that you are consistent. If two computers are going to communicate in Ad-Hoc mode, configure each computer with an IP address from the same class, such as the two class A IP addresses 10.0.0.1 and 10.0.0.2.
Successfully configuring a computer to participate on your home or small office WiFi network requires that you configure the computer for workgroup participation (that is, you must give the computer a name and its appropriate workgroup settings). You must also configure the computer so that it receives a valid IP address and subnet mask from your WiFi router or you must configure the computer or computers with static IP addresses when operating the WiFi network in Ad-Hoc mode (meaning that no WiFi router is present to provide the IP addresses). When you have configured all these items correctly, the computer can browse the network for other workgroup members and access network services.