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

Get Networking Explained, 2nd Edition now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.