- Oct 4, 2002
Sorting Through Local Area Network Protocols
A network protocol is a set of rules and procedures for communicating and exchanging data over a network. Windows networks operate using a number of different networking protocols. These protocols can be thought of as operating at three different logical layers as depicted in the following three-layered model shown in Figure 3.8.
Figure 3.8 Windows-based networks use a number of protocols, each of which provides a different type of functionality.
Protocols operating at the bottom level of this networking model:
Are known as hardware protocols or access methods
Specify how network data is transported over the network
Determine how data is exchanged between any two network devices or computers
Determine how improperly formatted data is handled
Protocols operating at the middle layer of this networking model:
Are known as software protocols or transport protocols
Specify how network hardware communicates
Determine how network data is organized into packets and sent across the network
Depend on the services provided by lower-level protocols
Protocols operating at the upper layer of this networking model:
Determine how the operating system and its software will communicate
Depend on the services of middle-layer protocols
A home network consists of a number of protocols, each of which has a specific function and all of which must work together.
Access Methods: Bottom Level of Networking Model
The lowest-level protocol that will run on your home network is the access method. Access method protocols determine:
The format in which data is to be transmitted over a network
When computers and network devices are permitted to transmit network data
How data collisions are handled
Access method protocols are implemented based on the selection of network adapters. They are loaded on your computer when the software driver for your network adapter is installed. There are a number of competing access methods including
EthernetThis is the current standard for local area networks and is the only viable choice for a home network.
Token RingThis is an older protocol pioneered by IBM, which has lost favor in recent years.
FDDIThis access method applies to fiber-optic networks and is not appropriate for home networking.
The selection of your type of network, and therefore, of your network cards, determines the selection of your network's access method.
Transport Protocols: Middle Level of Networking Model
Although you really do not have a choice in the type of low-level protocol or access method that your network will use, you do have a lot more flexibility in selecting which middle-level protocol or transport protocol you'll run on your network.
Actually you can run two or more protocols at the same time on your home network if you have a need. However, when you use multiple protocols you use up more of your network's bandwidth and place a greater demand on your network computer processors. An important part of tuning your network and keeping it running at full speed involves removing any unnecessary protocols from your computers. As you learn in just a few minutes, there is really only one protocol that you need to run anyway.
You have three transport protocols to choose from when setting up your network. They are
NetBEUIA simple protocol that is easy to install and that requires no maintenance. This protocol is good for small networks but does not support Internet access.
IPX/SPXThis is a very sophisticated protocol developed by Novell for the NetWare networks. However, it has lost much of its luster in recent years and has, for the most part, been replaced by TCP/IP.
TCP/IPThis is the protocol of the Internet. It's also the default protocol installed by Windows XP whenever a network adapter is installed and most likely is the only protocol that you need to run on your home network.
Windows XP Home Edition supports all three of these protocols. Each protocol has a separate and distinct set of rules and standards that makes it incompatible with other protocols, meaning that it can only communicate with other computers running the same protocol. Of the three protocols, the only one that you need to use is TCP/IP. It is the only one of these protocols that supports Internet and local area network communications.
NetBEUI: The Little Protocol That Could
NetBIOS Extended User Interface, or NetBEUI, is a small but fast protocol developed by IBM and Microsoft in the mid-1980s. It is faster than TCP/IP and IPX/SPX and requires a small amount of memory overhead on each computer. It was designed to support small department-sized networks with no more than 50 computers. NetBEUI is a simple self-configuring protocol that requires no administrative overhead after its initial installation. Its major drawback is that it lacks support for routing.
The best use for NetBEUI is to help troubleshoot a failed attempt to set up a home network. If after installing your hardware and setting up your home network, nothing seems to be working, you can install NetBEUI on every network computer and see what happens. If things begin working and your computers can now see one another, then you'll know that there is nothing wrong with your network adapters, wiring, or basic configuration. Most likely the problem lies with the configuration of TCP/IP.
A router is a hardware device that connects two or more networks. Larger corporations usually divide their networks into small networks or subnets and then connect everything with routers. By dividing a larger network into a number of small subnets you are able to isolate network traffic to specific subnets and reduce the overall demands on the total network. Routers are designed to allow network traffic to flow from one subnet to another but only allow network data to pass through if it's specifically addressed to another subnet. IPX/SPX and TCP/IP both support routing between subnets.
As I have already stated, NetBEUI does not require any configuration or administration on your part. You simply install it and it works. Microsoft Windows 95 loads NetBEUI as its default network protocol. NetBEUI is a good protocol for a home network. However, ever since Windows 98, Microsoft has replaced NetBEUI with TCP/IP as the default protocol for Microsoft operating systems. One reason for this is the almost universal acceptance that TCP/IP has achieved in recent years. Another is that even if you run NetBEUI, you are still going to need to load TCP/IP to connect to the Internet.
Microsoft discourages the use of NetBEUI as a home networking protocol. In fact, it does not even list NetBEUI as an available protocol. However, you will find it buried on the Windows XP Home Edition CD-ROM in \VALUEADD\MSFT\NET\NETBEUI.
The following procedure outlines how to install NetBEUI and can also be used as a general procedure for installing other network protocols, although each protocol installs a little differently.
- Click Start and then select My Network Places. The My Network Places dialog box appears as shown in Figure 3.9.
Figure 3.9 The My Network Places dialog box is the focal point where you'll manage most of your computer's network configuration.
Click View Network Connection in the upper-left pane. You'll see a dialog box displaying an icon representing your Local Area Connection as shown in Figure 3.10.
Right-click the Local Area Connection icon and select Properties. The Local Area Connection Properties dialog box appears as shown in Figure 3.11. This dialog box displays a list of all currently installed network clients, services, and protocols. As you can see, TCP/IP is already installed on this computer.
Figure 3.10 Viewing your local area connection.
Figure 3.11 Examining currently installed clients, services, and protocols.
Click Install. The Select Network Component Type dialog box appears as shown in Figure 3.12.
Select Protocol and click Add. The Select Network Protocol dialog box appears as shown in Figure 3.13.
Figure 3.12 You can install additional clients, services, and protocols.
Figure 3.13 Viewing a list of available protocols.
NetBEUI is not displayed. It is located on the Windows XP Home Edition CD-ROM. To Select it click Have Disk. Type X:\VALUEADD\MSFT\NET\NETBEUI when prompted to supply the location of the protocol (X: represents your CD-ROM drive) and click OK.
The Select Network Protocol dialog box appears displaying NetBEUI as an entry. Select the NetBEUI Protocol entry and click OK as shown in Figure 3.14.
Windows XP installs NetBEUI and then displays a dialog box asking for permission to restart your computer. Until the computer is restarted, the new protocol will not be available to the system. Click Yes to restart your computer.
As long as you are using TCP/IP you do not need to run any other protocols and should remove them. This will free up resources on your computer and reduce your network traffic.
Figure 3.14 You can install NetBEUI after locating it on the Windows XP Home Edition CD-ROM.
IPX/SPX: NetWare's Proprietary Protocol
IPX/SPX is a proprietary protocol developed by NetWare for its Novell network operating system. Microsoft implements IPX/SPX under the name of NWLink IPX/SPX/NetBIOS Compatible Transport Protocol. As a proprietary protocol only NetWare is permitted to make changes to it, as opposed to TCP/IP where thousands of different people and organizations participate in the protocol's development.
Novell developed this protocol based on the Xerox XNS protocol. IPX/SPX has been the default network protocol on all NetWare networks up to version 4.X. However, starting with NetWare 5.X, Novell began making TCP/IP its default protocol. Therefore, it's a pretty safe bet that, like NetBEUI, IPX/SPX's days are numbered.
IPX/SPX is a little slower than NetBEUI. But like TCP/IP, it runs well on networks that have been divided into multiple subnets. Its major drawback is that it is not supported on the Internet. IPX/SPX is sometimes used on corporate networks to connect computers to older NetWare networks. Although it can certainly serve as the main transport protocol on your home network, you'll find that you'll still need to run TCP/IP to connect to the Internet.
Even if you choose not to install IXP/SPX on your home network, you may find that it sneaks its way onto your computer. This can happen because a number of network-based computer games use IPX/SPX and will automatically install it on any computer where you install the game. There is no harm in this. However, if you ever decide to uninstall your network games(s) you should also remember to uninstall IPX/SPX as well. After all, it consumes valuable computer resources and adds unnecessary traffic to your home network.
TCP/IP: The Protocol of the Internet
As I stated earlier, TCP/IP is probably the only transport protocol that you'll need to run on each computer on your home network. TCP/IP is the protocol of the Internet. It was designed to run on the Internet and only found its way to local area networks at a later date. For years it has been the choice of large corporate networks. However, Microsoft has now embraced it as the transport protocol of choice for all networks, large and small.
TCP/IP was created in 1969 as part of the Department of Defense's ARPAnet network. ARPAnet was an early wide area network designed to survive a nuclear attack. It was designed to be able to suffer from multiple failures and keep on operating.
TCP/IP is actually a large suite of related protocols that work together. A list of TCP/IP protocols includes:
ARPA protocol used to locate the hardware addresses of network computers using their IP address
DHCPA protocol that automatically assigns IP configuration data to network computers
FTPA file transfer protocol used to transport files
ICMPA protocol that reports on packed delivery errors
RARPA protocol used to locate a network computer's IP address when using its hardware address
SMTPAn electronic mail transfer protocol
TelnetA protocol that supports remote terminal access
UDPA protocol similar to TCP except that it does not provide the guaranteed delivery of data
TCP/IP is slower than NetBEUI and IPX/SPX. It also requires more configuration than either of these two protocols. This might make TCP/IP seem inappropriate for small home networks; however, Microsoft has worked hard to make using TCP/IP much easier on any size network.
TCP/IP is the default protocol for Windows XP and for all other Microsoft operating systems since Windows 98. It is automatically installed and configured during the network adapter installation process. Microsoft has done much to simplify and automate the installation and configuration of TCP/IP. Windows XP includes an automatic IP address assignment feature that has actually been around since Windows 98, which allows every Windows XP computer to automatically configure its TCP/IP settings. This feature enables Windows XP to prepare your computer to participate on any network.
TCP/IP uses IP address to identify computers on a network. Every computer must have a unique IP address that belongs to the same logical network, in order for everything to work.
If you are not already familiar with TCP/IP addressing, then you should take a look at Appendix B, "TCP/IP Basics," before continuing with the rest of this section. This appendix will provide you with a basic review of TCP/IP and how it works. As you may already be aware, TCP/IP is a very complex topic. If you'd like to learn more about it, check out Special Edition Using TCP/IP from Que.
When a Windows XP computer connected to a home network starts up it will automatically assign itself a temporary IP address on a Class B network of 169.254.0.0 with a subnet mask of 255.255.0.0. No additional configuration is required for you to set up your peer network. The TCP/IP network address of 169.254.0.0 is a special reserved network address. No company or organization connected to the Internet is permitted to use it.
If you are going to have Windows 95 or Windows NT Workstation 4.0 systems attached to your home network, then you will have to manually configure these operating systems to participate on your 126.96.36.199 network. Neither of these operating systems provides for its own automatic IP address configuration. You can assign any IP address in the range of 169.254.0.1 to 188.8.131.52 to these computers. Just remember to assign a subnet mask of 255.255.0.0 to each computer. Make sure that you start the computers that you manually configured first. Windows computers that implement automatic IP addressing check to make sure that an IP address is not in use on the network before assigning it to themselves. If you turn on a Windows 95 or NT computer that has an IP address that has already been self-assigned by another computer, an IP address conflict will occur. The Windows 95 or NT computers will not be able to operate on the network and you'll either have to assign a new address to the Windows 95 or NT computer or restart the conflicting computer in order to allow it to reassign itself a different IP address.
If you prefer, you can manually configure the TCP/IP address settings on your Windows XP computer instead of allowing Windows XP to do it for you as outlined in the following procedure. It's up to you. If you decide to manually assign the IP address of some of your Windows XP computers, remember to assign them an IP address between 169.254.0.1 and 169.254.0.254 and to assign them a subnet mask of 255.255.0.0.
Click Start and then select My Network Places. The My Network Places dialog box appears.
Click View Network Connection in the upper-left pane.
Right-click the Local Area Connection icon and select Properties. The Local Area Connection Properties dialog box appears.
Click Internet Protocol (TCP/IP) and click Properties. The Internet Protocol (TCP/IP) Properties dialog box appears as shown in Figure 3.15.
Select Use the Following IP Address. Type an IP address in the range of 169.254.0.1 and 169.254.0.254 in the IP address field. Type 255.255.0.0 in the Subnet mask field. For now leave the Default gateway field blank. Likewise leave the DNS fields at the bottom of the dialog box clear.
For more information on these fields see "Setting Up Shared Internet Access with an Internet Gateway" in Chapter 8, "Going Online."
- Click OK. Click Close when returned to the Local Area Connection Properties dialog box.
Figure 3.15 Manually configuring the TCP/IP settings on a Windows XP computer.
It is easy to tell what your TCP/IP configuration settings are if you manually configure them. However, they are not so apparent if you allow Windows XP to automatically configure them. You can view your computer's TCP/IP configuration by executing the IPCONFIG command from the Windows command prompt.
The Windows command prompt is a text-based interface that allows you to communicate with the operating system by typing in text commands and reviewing command text output.
If you are a Windows 95, 98, or ME user, then you may be used to working with the WINIPCFG command. This command provides the same information as the IPCONFIG command does on Windows NT, 2000, and XP.
The following procedure outlines the use of the IPCONFIG command to view your computer's TCP/IP settings.
Open the Windows Command prompt by clicking Start, All Programs, Accessories, and then Command prompt.
Type IPCONFIG and press enter to view the TCP/IP configuration settings for the computer local area connection as demonstrated in Figure 3.16.
To view additional TCP/IP configuration settings or to view other network connections type IPCONFIG /ALL and press Enter.
When done reviewing the results of the IPCONFIG command type EXIT and press Enter to close the Windows command prompt.
Figure 3.16 Using IPCONFIG to view Windows XP's TCP/IP configuration settings.
To learn more about working with the IPCONFIG command refer to Appendix A, "Windows XP Net Commands."
Network Client: Upper Level of Networking Model
The third level of network protocols determines how the operating system and its applications will communicate. These protocols are provided in the form of network clients. For home networks running Microsoft's operating system, the required client is the Client for Microsoft Networks. The Client for Microsoft Networks provides Windows XP with the ability to access and use network services. It is automatically installed by default by Windows XP when your network adapter is installed.
A standalone computer not connected to a network has access to its own resources, which include its printers and local disk drives. When connected to a local area network the computer must run a network client to be able to access network resources. The network client acts as a redirector. A redirector intercepts requests to access hardware resources and determines where the resource resides. If the resource is local to the computer, the request is permitted to process normally. However, if the request is for a network resource, the redirector steps in and redirects the request out over the network.