Introduction to Wireless Network Security

It wasn’t too long ago that computers were a luxury rather than a necessity. Only the lucky and the wealthy had even one in their home and a network was something reserved for large corporations.

Fast forward a decade or so and everyone has to have their own computer. There is one for the parents (sometimes two if the parents can’t share nice) and one or more for the kids to use for homework and games. Home users have gone from no Internet access to 9600 kbps dial-up Internet access beyond 56 kbps dial-up access and are moving on to broadband connections to rival or match the T1 connections they relish at work.

As the Internet and the World Wide Web have exploded into our culture and are replacing other media forms for people to find news, weather, sports, recipes, yellow pages and a million other things, the new struggle is not only for time on the computer at home, but for time on the Internet connection.

The hardware and software vendors have come forth with a variety of solutions allowing home users to share one Internet connection among two or more computers. They all have one thing in common though- the computers must somehow be networked.

To connect your computers together has traditionally involved having some physical medium running between them. It could be phone wire, coaxial cable or the ubiquitous CAT5 cable. Recently hardware has been introduced that even lets home users network computers through the electrical wiring. But, one of the easiest and least messy ways to network computers throughout your home is to use wireless technology.

It is a fairly simple setup. The Internet connection comes in from your provider and is connected to a wireless access point or router which broadcasts the signal. You connect wireless antenna network cards to your computers to receive that signal and talk back to the wireless access point and you are in business.

The problem with having the signal broadcast though is that it is difficult to contain where that signal may travel. If it can get from upstairs to your office in the basement then it can also go that same 100 feet to your neighbor’s living room. Or, a hacker searching for insecure wireless connections can get into your systems from a car parked on the street.

That doesn’t mean you shouldn’t use wireless networking. You just have to be smart about it and take some basic precautions to make it more difficult for curiosity seekers to get into your personal information. The next section contains some simple steps you can take to secure your wireless network.

To maximize benefit from the directions below, have your answers ready for the following questions:

· Do you want to extend your wired home network with a WLAN, or are you building a completely new network?
· How many wireless computers do you plan to network, and where in the home will be they be located?
· what operating systems do/will you run on your networked computers?
· Do you need to share your Internet connection among the wireless computers? how else will you use this WLAN? file sharing? Network gaming?

Installing a Wireless Router
One wireless router supports one WLAN. Use a wireless router on your network if:
· you are building your first home network, or
· you want to re-build your home network to be all-wireless, or
· you want to keep your WLAN installation as simple as possible

Try to install your wireless router in a central location within the home. The way Wi-Fi networking works, computers closer to the router (generally in the same room or in "line of sight") realize better network speed than computers further away.
Connect the wireless router to a power outlet and optionally to a source of Internet connectivity. All wireless routers support broadband modems, and some support phone line connections to dial-up Internet service. If you need dial-up support, be sure to purchase a router having an RS-232 serial port. Finally, because wireless routers contain a built-in access point, you're also free to connect a wired router, switch, or hub.
Next, choose your network name. In Wi-Fi networking, the network name is often called the SSID. Your router and all computers on the WLAN must share the same SSID. Although your router shipped with a default name set by the manufacturer, it's best to change it for security reasons. Consult product documentation to find the network name for your particular wireless router, and follow this general advice for setting your SSID.
Last, follow the router documentation to enable WEP security, turn on firewall features, and set any other recommended parameters.

Installing a Wireless Access Point
One wireless access point supports one WLAN. Use a wireless access point on your home network if:
· you don't need the extra features a wireless router provides AND
· you are extending an existing wired Ethernet home network, or
· you have (or plan to have) four or more wireless computers scattered throughout the home

Install your access point in a central location, if possible. Connect power and a dial-up Internet connection, if desired. Also cable the access point to your LAN router, switch or hub.

You won't have a firewall to configure, of course, but you still must set a network name and enable WEP on your access point at this stage.

Configuring the Wireless Adapters
Configure your adapters after setting up the wireless router or access point (if you have one). Insert the adapters into your computers as explained in your product documentation. Wi-Fi adapters require TCP/IP be installed on the host computer.
Manufacturers each provide configuration utilities for their adapters. On the Windows operating system, for example, adapters generally have their own graphic user interface (GUI) accessible from the Start Menu or taskbar after the hardware is installed. Here's where you set the network name (SSID) and turn on WEP. You can also set a few other parameters as described in the next section. Remember, all of your wireless adapters must use the same parameter settings for your WLAN to function properly.

Configuring an Ad-Hoc Home WLAN
Every Wi-Fi adapter requires you to choose between infrastructure mode (called "access point" mode in some configuration tools) and ad-hoc ("peer to peer") mode. When using a wireless access point or router, set every wireless adapter for infrastructure mode. In this mode, wireless adapters automatically detect and set their WLAN channel number to match the access point (router).
Alternatively, set all wireless adapters to use ad hoc mode. When you enable this mode, you'll see a separate setting for channel number. All adapters on your ad hoc wireless LAN need matching channel numbers.
Ad-hoc home WLAN configurations work fine in homes with only a few computers situated fairly close to each other. You can also use this configuration as a fallback option if your access point or router breaks:

Configuring Software Internet Connection Sharing
As shown in the diagram, you can share an Internet connection across an ad hoc wireless network. To do this, designate one of your computers as the host (effectively a substitute for a router). That computer will keep the modem connection and must obviously be powered on whenever the network is in use. Microsoft Windows offers a feature called internet connection sharing(ICS) that works with ad hoc WLANs.

The building blocks of a wireless LAN are network adapters, access points, wireless routers, add-on wireless antennas and signal boosters. Of these, only network adapters are truly required to build a wireless home network. However, many wireless LANs also utilize some of the other equipment, as explained below.

Wireless Network Adapters
Each computer you wish to connect to a WLAN must possess a wireless network adapter. Wireless adapters are sometimes also called NICs, short for Network Interface Cards. Wireless adapters for desktop computers are often small PCI cards or sometimes card-like USB adapters. Wireless adapters for notebook computers resemble a thick credit card .Nowadays, though, an increasing number of wireless adapters are not cards but rather small chips embedded inside notebook or handheld computers.

Wireless network adapters contain a radio transmitter and receiver (transceiver). Wireless transceivers send and receive messages, translating, formatting, and generally organizing the flow of information between the computer and the network. Determining how many wireless network adapters you need to buy is the first critical step in building your home network. Check the technical specifications of your computers if you're unsure whether they contain built-in wireless adapter chips.

Wireless Access Points
A wireless access point serves as the central WLAN communication station. In fact, they are sometimes called "base stations." Access points are thin, lightweight boxes with a series of LED lights on the face .

Access points join a wireless LAN to a pre-existing wired Ethernet network. Home networkers typically install an access point when they already own a broadband router and want to add wireless computers to their current setup. You must use either an access point or a wireless router (described below) to implement "hybrid" wired/wireless home networking. Otherwise, you probably don't need an access point.

Wireless Routers
A wireless router is a wireless access point with several other useful functions added. Like wired broadband routers, wireless routers also support Internet connection sharing and include firewall technology for improved network security. Wireless routers closely resemble access points .

A key benefit of both wireless routers and access points is scalability. Their strong built-in transceivers are designed to spread a wireless signal throughout the home. A home WLAN with a router or access point can better reach corner rooms and backyards, for example, than one without. Likewise, home wireless networks with a router or access point support many more computers than those without one. As we'll explain in more detail later, if your wireless LAN design includes a router or access point, you must run all network adapters in so-called infrastructure model; otherwise they must run in ad-hoc mod.

Wireless Antennas
Wireless network adapters, access points, and routers all utilize an antenna to assist in receiving signals on the WLAN. Some wireless antennas, like those on adapters, are internal to the unit. Other antennas, like those on many access points, are externally visible. The normal antennas shipped with wireless products provide sufficient reception in most cases, but you can also usually install an optional, add-on antenna to improve reception. You generally won't know whether you'll need this piece of equipment until after you finish your basic network setup.

Wireless Signal Boosters
Some manufacturers of wireless access points and routers also sell a small piece of equipment called a signal booster. Installed together with a wireless access point or router, a signal booster serves to increase the strength of the base station transmitter. It's possible to use signal boosters and add-on antennas together, to improve both wireless network transmission and reception simultaneously.

Both antennas and signal boosters can be a useful addition to some home networks after the basics are in place. They can bring out-of-range computers back into range of the WLAN, and they can also improve network performance in some cases.

Next - WLAN Configurations
Now that you have a good understanding of the pieces of a wireless LAN, we're ready to set them up according to your needs. Don't worry if you haven't settled on a configuration yet; we will cover all of them.

When researching wireless equipment to buy, or talking about wireless networking with friends and family, you should have a solid understanding of this basic terminology.

What is a WLAN?
We've already said that a WLAN is a "typical" wireless home network. That's because a WLAN is a wireless LAN, and a LAN is a related group of networked computers situated in close physical proximity to each other. LANs can be found in many homes, schools, and businesses. Though it's technically possible to have more than one LAN in your home, few do this in practice. In this tutorial, we explain how to build a single standard WLAN for your home.

What is Wi-Fi?
Wi-Fi is an industry name used to market wireless networking products. You'll find a black-and-white Wi-Fi logo or certification emblem on virtually any new wireless equipment you buy. Technically speaking, Wi-Fi signifies conformance to the 802.11 family of wireless communication standards (described below). But because all mainstream wireless home network gear uses the 802.11 standards today, basically the term "Wi-Fi" merely distinguishes wireless equipment from other network gear.

What is 802.11a/802.11b/802.11g?
802.11a, 802.11b, and 802.11g represent three popular wireless communication standards. Wireless networks can be built using any of the three, but 802.11a is less compatible with the others and tends to be a more expensive option implemented only by larger businesses. Use the supplemental article below to help you pick 802.11 standard(s) for your wireless LAN.

What are WEP and Wardriving?
The security of wireless home and small business networks remains a concern for many. Just like we use radio or television receivers to tune into station broadcasts, it's almost as easy to pick up signals from a nearby wireless home network. Sure, credit card transactions on the Web may be secure, but imagine your neighbors spying on every email and instant message you send!
A few years ago, some techies popularized the practice of wardriving to raise awareness of this vulnerability in WLANs. With the help of cheap, home-made equipment, "wardrivers" walked or motored through neighborhoods snooping the wireless network traffic emanating from nearby homes. Some wardrivers even logged their computers onto unsuspecting people's home WLANs, essentially stealing free computer resources and Internet access.
WEP is an important feature of wireless networks designed to improve security. WEP scrambles (technically speaking, encrypts) network traffic mathematically so that other computers can understand it, but humans cannot read it. WEP helps protect your WLAN from wardrivers and nosy neighbors, and today, all popular wireless equipment supports it. Because WEP is a feature that can be turned "on" or "off," you'll simply need to ensure it is configured properly when setting up your network.

Next - Types of Wireless Equipment
The five types of equipment found in wireless home networks are:
· wireless network adapters
· wireless access points
· wireless routers
· add-on wireless antennas
· wireless signal boosters

Some of this equipment is optional depending on your home network configuration. Let's examine each piece in turn.

How to Build a Wireless Home Network

Introduction to wireless computer networking

Benefits of Wireless
Wireless offers tangible benefits over traditional wired networking. Ever tried to quickly look up a recipe on the Net while cooking in the kitchen? Do the kids need a networked computer in their bedroom for school projects? Have you dreamed of sending email, instant messaging, or playing games while relaxing on your outdoor patio? These are just some of the things wireless can do for you:

Question: What Are the Benefits of Networking?
Answer: The benefits of networking (either wired or wireless) in homes are:

· file sharing - Network file sharing between computers gives you more flexibity than using floppy drives or Zip drives. Not only can you share photos, music files, and documents, you can also use a home network to save copies of all of your important data on a different computer. Backups are one of the most critical yet overlooked tasks in home networking.

printer / peripheral sharing - Once a home network is in place, it's easy to then set up all of the computers to share a single printer. No longer will you need to bounce from one system or another just to print out an email message. Other computer peripherals can be shared similarly such as network scanners, Web cams, and CD burners.

Internet connection sharing - Using a home network, multiple family members can access the Internet simultaneously without having to pay an ISP for multiple accounts. You will notice the Internet connection slows down when several people share it, but broadband Internet can handle the extra load with little trouble. Sharing dial-up Internet connections works, too. Painfully slow sometimes, you will still appreciate having shared dial-up on those occasions you really need it.
multi-player games - Many popular home computer games support LAN mode where friends and family can play together, if they have their computers networked.

Internet telephone service - So-called Voice Over IP (VOIP) services allow you to make and receive phone calls through your home network across the Internet, saving you money.

home entertainment - Newer home entertainment products such as digital video recorders (DVRs) and video game consoles now support either wired or wireless home networking. Having these products integrated into your network enables online Internet gaming, video sharing and other advanced features.
Although you can realize these same benefits with a wired home network, you should carefully consider building a wireless home network instead, for the following reasons:

1. Computer mobility. Notebook computers and other portable devices are much affordable than they were a few years ago. With a mobile computer and wireless home network, you aren't chained to a network cord and can work on the couch, on your porch, or wherever in the house is most convenient at the moment.
2. No unsightly wires. Businesses can afford to lay cable under their floors or inside walls. But most of us don't have the time or inclination to fuss with this in our home. Unless you own one of the few newer homes pre-wired with network cable, you'll save substantial time and energy avoiding the cabling mess and going wireless.
3. Wireless is the future. Wireless technology is clearly the future of networking. In building a wireless home network, you'll learn about the technology and be able to teach your friends and relatives. You'll also be better prepared for future advances in network technology coming in the future.