Upgrading and Repairing PCs

Network Protocols

The second-most important choice you must make when you create your network is which network protocol to use. The network protocol affects which types of computers your network can connect.

The three major network protocols are TCP/IP, IPX/SPX, and NetBEUI. Unlike data-link protocols, though, network protocols are not tied to particular hardware (NIC or cable) choices. Network protocols are software and can be installed to or removed from any computer on the network at any time as necessary. Table 20.11 summarizes the differences between these protocols.

Table 20.11. Overview of Network Protocols and Suites

Protocol	Included in Protocol Suite	Best Used for	Notes
IP	TCP/IP	Internet and large networks	Also used for dialup Internet access; native protocol suite of Windows 2000 and XP and Novell NetWare 5.x and 6.x
IPX	IPX/SPX	Networks with Novell 4.x and earlier servers	Used by NetWare 5.x for certain special features only
NetBEUI	N/A	Windows 9x, 2000, or Windows for Workgroups peer networks	Can't be routed between networks; simplest network protocol; also used with Direct Cable Connection NIC-less "networking"; not supported in Windows XP, but can be installed manually from the Windows XP CD-ROM for troubleshooting

All the computers on any given network must use the same network protocol or protocol suite to communicate with each other.

IP and TCP/IP

IP stands for Internet Protocol; it is the network layer of the collection of protocols (or protocol suite) developed for use on the Internet and commonly known as TCP/IP (Transmission Control Protocol/Internet Protocol).

Later, the TCP/IP protocols were adopted by the Unix operating systems, and they have now become the most commonly used protocol suite on PC LANs. Virtually every operating system with networking capabilities supports TCP/IP, and it is well on its way to displacing all the other competing protocols. Novell NetWare 6 and Windows XP both use TCP/IP as their native protocol for most services.

TCP/IP—LAN and Dialup Networks

TCP/IP, unlike the other network protocols listed in the previous section, is also a protocol used by people who have never seen a NIC. People who access the Internet via modems (with what Windows 9x calls Dial-Up Networking) use TCP/IP just as those whose Web access is done with their existing LANs. Although the same protocol is used in both cases, the settings vary a great deal.

Table 20.12 summarizes the differences you're likely to encounter. If you access the Internet with both modems and a LAN, you must ensure that the TCP/IP properties for modems and LANs are set correctly. You also might need to adjust your browser settings to indicate which connection type you are using. Table 20.12 provides general guidelines; your ISP or network administrator can give you the specific details.

Table 20.12. TCP/IP Properties by Connection Type—Overview

TCP/IP Property Tab	Setting	Modem Access (Dialup Adapter)	LAN Access (Network Card)
IP Address	IP Address	Automatically assigned by ISP	Specified (get value from network administrator) or automatically assigned by a DHCP server on the network (DHCP servers are often built in to gateways and routers)
WINS Configuration	Enable/Disable WINS Resolution	Disabled	Indicate server or enable DHCP to allow NetBIOS over TCP/IP
Gateway	Add Gateway/List of Gateways	None (PPP is used to connect modem to Internet)	IP address of gateway used to connect LAN to Internet
DNS Configuration	Enable/Disable Host Domain	Usually disabled, unless proxy server used by ISP	Enabled, with host and domain specified (get value from network administrator)

As you can see from Table 20.12, correct settings for LAN access to the Internet and dialup networking (modem) settings are almost always completely different. In general, the best way to get your dialup networking connection working correctly is to use your ISP's automatic setup software. This is usually supplied as part of your ISP's signup software kit. After the setup is working, view the properties and record them for future troubleshooting use.

Note In Windows 98 and Me, Microsoft recommends that TCP/IP properties be viewed through the Dial-Up Networking icon for the connection, rather than through the Network icon in the Control Panel. This is because different dialup connections could use different TCP/IP properties, which would override the default properties for the Dial-Up Adapter listing in the Network properties. In Windows 2000 and XP, all types of networking are viewed and configured through a single interface.

IPX

The IPX protocol suite (often referred to as IPX/SPX) is the collective term for the proprietary protocols Novell created for its NetWare operating system. Although based loosely on some of the TCP/IP protocols, Novell privately holds the IPX protocol standards. However, this has not prevented Microsoft from creating its own IPX-compatible protocol for the Windows operating systems.

IPX (Internetwork Packet Exchange) itself is a network layer protocol that is equivalent in function to IP. The suite's equivalent to TCP is the Sequenced Packet Exchange (SPX) protocol, which provides connection-oriented, reliable service at the transport layer.

The IPX protocols typically are used today only on networks with NetWare servers running older versions of NetWare and often are installed along with another protocol suite, such as TCP/IP. Novell has phased out its use of IPX for NetWare support and switched to TCP/IP—along with the rest of the networking industry—starting with NetWare 5. NetWare 5 uses IPX/SPX only for specialized operations. Most of the product uses TCP/IP. NetWare 6, the latest version of NetWare, uses TCP/IP exclusively.

NetBEUI

NetBIOS Extended User Interface (NetBEUI) is a protocol used primarily on small Windows NT networks, as well as on peer networks based on Windows for Workgroups and Windows 9x. It was the default protocol in Windows NT 3.1, the first version of that operating system. Later versions, however, use the TCP/IP protocols as their default.

NetBEUI is a simple protocol that lacks many of the features that enable protocol suites such as TCP/IP to support networks of almost any size. NetBEUI is not routable, so it can't be used on large internetworks. It is suitable for small peer-to-peer networks, but any serious Windows NT/2000/XP network installation should use TCP/IP.

NetBEUI is still useful for creating "instant networks" with the Direct Cable Connection (see the following), and it is the minimum protocol required for use in a Windows 9x peer-to-peer network.