If you are merely adding a new or upgraded laptop to an existing wired net-
work, all you need on the hardware side is the NIC and an Ethernet cable.On the other hand, if you are creating a network from scratch, here are the
hardware components:NICsfor all computers. If not already installed on your laptop, they can
be added to a PC Card slot or (preferably) to a USB port. Some devices
can also be added to a network and used as a device by any attached
computer; as an example, some printers can be network attachedwith a
specialized NIC and circuitry.
A hubto serve as the central connection point for cables from comput-
ers and other devices. The hub can also be connected to a router and
broadband modem (more about these in a moment). The hub (some
techies call it a concentrator) can also be used to connect two networks
or to connect to a wireless transmitter to extend into a WiFi(wireless
fidelity) system; in that use it is considered a router.If you add in a hard-
ware firewallas one layer of protection against Internet pirates and
ne’er-do-wells, what you’ve got is a gateway,a combination of switch,
router, and firewall.An intelligent version of a hub is called a switch,and it speeds up the
process by connecting directly from the sending device to the receiving
device without sending the packet all the way around the ring or down
the full length of the bus. In the process it cuts down on time-consuming
collisions (data packets bumping into each other). You can read about
these concepts in further depth in the accompanying “Ethernet for those
who have to know” sidebar.Building a Firewall........................................................................................
If I were in charge, the Internet would be fantastically fast, infinitely vast, virtu-
ally without cost... and most importantly, completely free of cyberjerks. I’ll
leave it to you to come up with an answer as to why some people dedicate
whole chunks of their otherwise empty lives to spoiling a good thing for others.
End of sermon, except to say that any user of the Internet — and especially
those who maintain an always-on, high-speed broadband connection — need
to erect hardware and software barriers against thieves and vandals.A hardware firewallworks by plugging the entryways into the network and
into attached computers except for those specifically granted permission to
come in. Firewalls are not perfect — a truly dedicated hacker may be able to
get through — nor do they fully protect against the contents of e-mails and
downloads that you permit to get through. (You have to be on guard against
those by yourself, and use a capable antivirus software program to sweep
your mail and downloads and block suspicious activities.)Chapter 13: Networks, Gateways, and Routers 201