Networking Explained, 2nd Edition

466 Networking Explained, Second Edition

27. Do attacks on home-based Internet connections happen that often?

Yes and they are expected to increase as more home owners subscribe to “always on”

Internet connections such as cable modem or xDSL service. One of the authors had a

friend who was fortunate enough to be one of the first in his neighborhood to get a cable

modem connection. He installed the proper hardware and software on the system, and life

was good. In the first week of operation, he left his PC on at all times and was, effectively,

hooked into the Internet 24 hours a day. In that timeframe, an unauthorized user got onto

his system and set up an IRC chat redirection program that allowed the hacker to get onto

chat groups, be as rude and obnoxious as desired, and seriously disturb the chat groups

that the hacker was attacking. In the process of this, the various larger chat bulletin board

systems traced the IP address back to the friend’s PC; then a lawyer got involved. The

friend first found out that something was amiss when he and his ISP received a “cease and

desist” letter that threatened a lawsuit. Since the friend had been out of town that whole

time, and since no one else had touched the system, it was investigation time. Examination

of the system showed that the hacker really had been there and how he gained access. The

software was deleted, the ISP helped explain things to the lawyer, and all went back to

normal. So, in a home networking environment, you have to take security seriously and

use the proper precautions just like the company environment unless you want to lose your

data, allow someone to set up camp on your system, or possibly have your privacy com-

promised in an ugly way.

28. OK. I now understand the various ways I can get connected to the Internet from

home and some of the risks involved in doing so. What I want to know now is how

do I establish a network within my home so that my computers can communicate

with one another?

What you are describing is the essence of a home-based LAN, which, as we men-

tioned in Chapter 1, is sometimes referred to as a personal area network (PAN). As is the

case for any networking endeavor, a home-based LAN requires some advanced planning

on what you want the network to do and how flexible it needs to be. For example: Will the

infrastructure be wired or wireless (or both)? What protocols do you want to support? Do

you want to share a printer? Do you want the computers to share the same Internet connec-

tion? What security measures will you implement? These are only some of the many ques-

tions you should consider. Furthermore, once you answer one of these questions, there

usually are several more nested questions that need answers.

29. Let’s start with the infrastructure.

This is a good place to begin—layer 1 of the OSI model. One approach to establishing

a home-based LAN is to use a wired topology. This involves connecting all of your hosts

via Category 5 UTP cable. As noted in previous chapters, Category 5 cable will support

10-Mbps and 100-Mbps Ethernet/802.3, which presumably will be your LAN protocol of

choice. If your LAN will be restricted to one room, then this is probably the best way to

set up your network. However, if your LAN will extend into other rooms within your

house, then you will have to retrofit these rooms with new cable. This can be costly if you