Picking Your Network Protocol
Your decision of what protocols to run on your LAN is driven by what you expect your network to do. You can use the simple, straightforward NetBEUI protocols if you're simply setting up a new, small LAN for file and printer sharing, but you'll want heavier-duty protocols for more powerful applications. Here's how to decide what protocols you need to implement.
Choose the best network protocol based on the following types of systems:
Small standalone LAN with Windows-based computersA small LAN with only Windows computers and with no Internet connection needs only the NetBEUI protocols. The small size of the LAN implies that only hubs and switches are needed, not routers, while independence from the Internet implies that TCP/IP is not mandatory. TCP/IP will work well if you're willing to live with the added configuration required.
Small standalone LAN with a mix of Windows and Linux computers, or with print serversLinux machines are easiest to run under TCP/IP. Not only does it take extra work to run NetBEUI, but it's almost impossible not to run TCP/IP on Linux. Many standalone print servers and networked printers support only TCP/IP and the old Novell protocols (IPX/SPX). Consequently, if you run a LAN with non-Windows devices, you'll likely want to use only TCP/IP on the network. You'll have to set up TCP/IP addressing on both standalone and Internet-connected LANs; after you get past assigning addresses and names for each computer, TCP/IP on a standalone LAN is little more complicated than NetBEUI.
LAN connected to the InternetAside from Linux-based computers and standalone print servers, the compelling reason to run TCP/IP on your LAN is the Internet, which operates only with TCP/IP. As soon as you connect your LAN to the Internet, though, you run the risk of people attacking your systems.
LAN connected to the Internet through a firewallThe destination address in network messages received by your computer specifies the requested functionfor example, file-sharing messages have a part of the destination address that's different from print-sharing messages. As Figure 1 shows, you can improve your network security by adding a device known as a firewall between your LAN and the Internet to filter out messages from the Internet asking for services that you want to be accessible only to local computers.
Blocking disallowed traffic with a firewall
We recommend NetBEUI, TCP/IP, or both in all cases; there's simply no reason to bother with the old Novell protocols unless your LAN already has NetWare file servers that haven't been upgraded to TCP/IP, or unless you install standalone print servers that support only older Novell protocols.