Chapter 12. Local Area Networking

Computers are conspirators. They owe most of their success to deviously working together, subverting the established order like Bolsheviks plotting the overthrow of the Czar. Each computer by itself can be safely contained and controlled in a home or office. Linked together, however, and there's no telling what mischief they will get into. They might join together to pass subversive messages (which we call email). They might pool their resources so they can take advantage of powers beyond their capabilities and budgets (such as sharing a printer or a high-speed Internet connection). They can be each others' eyes and ears, letting them pry into affairs halfway around the world. They can gather information about you—even the most delicate personal matters, such as your credit card number—and share it with other conspirators (I mean "computers," of course) elsewhere in the world. They can just make your life miserable—oh wait, they did that when they weren't connected, too.

This computer conspiracy is the key to the power of the local area network and the Internet. It gives your computer more reach, more power, and more capabilities. It simply makes your life more convenient and your computer more connected. In fact, at one time local area networking was called connectivity.

Fortunately, computers themselves don't plot against you (although the people behind those computer may). Even when connected to a network, computers remain their obedient selves, ready to do your bidding.

The challenge you face in linking your computer to others is the same as faced by a child growing up with siblings—your computer has to learn to share. When kids share, you get more quiet, greater peace of mind, and less bloodshed. When computers share, you get the convenience of using the same files and other resources, centralized management (including the capability to back up all computers from one location or use one computer to back up others), and improved communication between workers in your business.

The drawback to connectivity is that computer networks are even more difficult to understand and manage than a platoon of teenagers. They have their own rules, their own value systems, their own hardware needs, and even their own language. Just listening in on a conversation between network pros is enough to make you suspect that an alien invasion from the planet Oxy-10 has succeeded. To get even a glimmer of understanding, you need to know your way around layers of standards, architectures, and protocols. Installing a network operating system can take system managers days; deciphering its idiosyncrasies can keep users and operators puzzled for weeks. Network host adapters often prove incompatible with other computer hardware, with their required interrupts and I/O addresses locking horns with SCSI boards, port controllers, and other peripherals. And weaving the wiring for a network is like threading a needle while wearing boxing gloves during a cyclone that has blown out the electricity, the candles, and your last rays of hope.

In fact, no one in his right mind would tangle with a network were not the benefits so great. File sharing across the network alone eliminates a major source of data loss, which is duplication of records and out-of-sync file updates. Better still, a network lets you get organized. You can put all your important files in one central location where they are easier to protect, both from disaster and theft. Instead of worrying about backing up half a dozen computers individually, you can easily handle the chore with one command. Electronic mail can bring order to the chaos of tracking messages and appointments, even in a small office. With network-based email, you can communicate with your coworkers without scattering memo slips everywhere. Sharing a costly laser printer or large hard disk (with some networks, even modems) can cut your capital cost of the computers' equipment by thousands or tens of thousands of dollars. Instead of buying a flotilla of personal laser printers, for example, you can serve everyone's hard copy needs with just one machine.