Welcome to Wireless Home Network Basics - the guide to setting up a basic Wireless LAN at home plus some security to keep it in place...

This guide is meant for the intermediate computer user and therefore kept to a bare minimum in terms of complicated jargon/lingo; and is meant to be easily understood and straight to the point.

Here is the table of contents:

1. Introduction: Wireless LAN - what is it? how to use it? features?

2. Standards: What are the standards you need to take into account?

3. Requirements: the stuff you need (hardware, software, cables)

4. Hardware setup: how to setup the hardware (placement, precautions)

5. Software setup: how to configure each computer (software, drivers, OS)

6. Router as a firewall: how to set up your router as a firewall for your network

7. Try it out: testing it, things you can do with it

8. Security: how to keep other people from using your Wireless LAN

Introduction

A Wireless Network, or Wireless LAN, or WLAN for short, is basically a computer network which links computers in an area. Normally, people use cables to connect computers together, however after wireless technology became popular, WLANs now use radio waves to transmit data between computers.

Several advantages of WLANs are:

• Inexpensive

• Less cabling involved

• Computers do not have to be bound by wires - in the case of laptops, more mobile

• A family can share an Internet connection

• Overall ease of use

WLANs do have downsides, which are:

• Lower bandwidth than LANs with cables (this is not noticeable in typical home networks)

• Security concerns (people can capture signals or illegally be part of your home WLAN)

• Radio waves have problems travelling through walls and obstructions (signal quality may be weak)

Standards

Standards are a very important aspect to consider when setting up a wireless network.

Right now there are 2 main standards for wireless networking in widespread use:

• 802.11b - This is the earliest standard of wireless networking. It supports speeds of up to 11mbps. It is important to note that this speed is attained under ideal conditions - walls, trees, and other structural limitations greatly decrease performance. However, even with that taken into account, this is typically enough bandwidth to distribute a 3-4 mbps high-speed internet connection.

• 802.11g - This is a newer standard for wireless networking. It supports speeds of 54mbps under ideal conditions. Like 802.11b, walls and other structural barriers greatly decrease the speed.

If anyone is setting up a new wireless network, using 802.11g equipment is recommended. This will set your network up to maintain an acceptable standard of performance well into the future.

An important point of information is that 802.11b and 802.11g are both "backward" and "forward" compatible with each other - that is, B cards will work with G routers, and vice versa. Note that if you use a B router with G cards, the cards will only work at 11mbps and not 54 mbps.

It has also been noted that if B cards are used with a G router in an area where G cards are also being used, the level of performance to the G cards suffers considerably.

Most vendors offer an enhanced performance version of the G card that operates at speeds in the 108mbps-125mbps range. These may be a worthwhile investment if you use all your equipment from one vendor, but only then it will work if you get the "performance enhanced" version of your router and all cards you want to benefit from enhanced performance.

For example, if you buy an enhanced performance D-link router, it will not work at high speeds with enhanced performance Linksys or Netgear cards. (Note that any card that is 802.11b or 802.11g compatible will work with all other 802.11b or g equipment. This statement specifically refers to the enhanced performance features of vendor-specific equipment).

Requirements

There are 2 major components to any wireless network.

• Router - This typically connects to your high-speed internet connection (cable/DSL). It typically also includes a built-in DHCP server to allocate IP Addresses to your network.

• Adapters - These are PC Cards for laptops or PCI cards for desktop computers that connect to the wireless network.

Special Notes:

It's possible to have a wireless network between two computers without a router. This is known as an "Ad Hoc" network.

If you have a computer without a wireless network card you want to connect to the network, a good idea would be to put the router by it. Most wireless routers include a number of LAN ports to which you can connect computers to the network that are not wifi-enabled.

Pricing:

• 802.11g routers can be found for as little as $20 in the US given various rebates and specials. "Enhanced Performance" routers can go for about $40 given rebates and incentives. If a router is bought without rebates, the price can be considerably higher.

• 802.11g adapters (both PCI and PC Card) can be found in relatively the same price range as routers in the same class (performance enhanced, or not) of the same manufacturer, given rebates and incentives.

Hardware Setup

The first topic I'd like to address in this section is router placement. This is very important to keeping a strong and consistent signal in your house.

First, consider the location of your cable or DSL modem. If this is in a central location in your house, great! If you are installing a new cable or DSL modem in your house, consider getting a central location for it.

If not, you can run more wiring in your house to get it to the router, or accept a weaker signal in the parts of the house farther from the router. If this is an issue, you may want to invest in a repeater that can bring your wireless signal to the far corners of your house.

The reason for this is that the more "obstacles" a wireless signal must pass through, the weaker the signal will be. In a home environment, here are some things to keep in mind:

• Wireless signals can pass through drywall relatively easily, but if it must pass through a significant number of walls the signal will degrade rapidly.

• Wireless signals do not travel well at all through cinder block walls.

• Water can greatly distort wireless signals. Take into account aquariums, sinks, and water pipes. Remember, the human body is 80% water, so locations with a high density of people can distort wireless signals.

• I have seen installations of wireless networks (particularly when traveling among a complex of buildings, such as a school) where network performance degrades rapidly when it's humid or raining.

If you want coverage among a patio or backyard (which can be very nice during good weather!) consider placing your router by a window overlooking the area you wish to cover. As always, make sure to secure your network so your neighbors can't get on it!

Wiring the router

Wiring your router is very easy if you follow a few simple steps.

1. Plug the ethernet cable from your cable or DSL modem into the "WAN" port of your router.

2. Plug any computers you wish to hard-wire to your router to one of the "LAN" ports. (if you want every computer to connect to the internet wirelessly, you do not need to do this)

3. Plug in the power cable and start it up!

Your router should start up with the default settings immediately. See the "security" section for the necessary steps to secure your network, since the default settings are very insecure.

Software Setup

All of the consumer routers I know of on the market today are configured via a web-based interface. To get to this, simply wire a computer to the LAN port and open your internet browser, then go to the web address specified in the documentation of your router.

D-Link routers are typically set to be at the IP address 192.168.0.1 by default. So, simply visit http://192.168.0.1 in your web browser. The user name for most D-Link routers is "admin" with no password.

Linksys routers default to being at the IP address 192.168.1.1. You can open the administration screens by opening http://192.168.1.1 in your web browser. The default password is "admin" with no user name (reverse of the D-Link).

After logging into your router the first time, it is best to secure your router using WPA and changing the default administrator password. See the Security section below for more details.

Modern operating systems such as Windows XP and Macintosh OS X include built in tools to make choosing and connecting to a wireless network easy. They include tools that scan the area for wireless networks and let you choose one to connect to.

Router as a Firewall

The vast majority of routers sold today offer simple firewall functionality. My recommendation: use it!

The firewall functionality is accessible through the web-based interface to your router. It may or may not be enabled by default, so be sure to set it up.

Why use a firewall?

A computer connected directly to the internet is a very high security risk. People with a minimal knowledge of hacking can connect directly to your computer and view your files, set up your machine as a "zombie" to send repeated requests to a website (along with thousands of other machines) to take it down (known as a Denial of Service attack), set up a mail relay on your computer to send SPAM, or worse.

A firewall prevents connections to your computer from the Internet, and only allows what your computer requests.

All computers connected directly to the Internet should have at the very least a software firewall, such as ZoneAlarm (available free on the internet) installed on it, but this is not always the case.

A hardware firewall, such as the one built into your router, provides much better protection than a software firewall.

Also note that you may have to adjust firewall settings to use certain software, such as Instant Messenger audio chat/video/file transfer, Netmeeting, or multiplayer gaming.

For more information on firewalls, visit the wikipedia entry for firewall.

Try it Out

Security

Why care about security?

You must consider security because you are legally responsible for any activity that goes on originating from you IP address. Your neighbors or possibly someone parked outside your house in a vehicle can access your internet connection and possibly commit illegal activity. The more likely scenario is that they would use your internet connection for free internet access.

A possibly greater threat would be access of private data stored on your computers.

Security becomes even more important if you are in a high-density location, such as an apartment complex or dormitory, where more people are likely to pick up your signal.

A good rule of thumb is:

Don't stick with the out-of-the-box settings!

It's fine to use the default settings when first setting up your network, but once settled in you will want to protect your network using a password protection mechanism called WPA (Wi-Fi Protected Access).

Choose a passphrase that is relatively long and contains both characters and numbers. Also, do *not* use "dictionary words" as these can be easily cracked. The more nonsensical your passphrase, the better. For example,

f7S9jeiF9M8254nZ8s

is more secure than the passphrase

toaster

For more information on choosing good passwords, visit Password Policy.

You should also change the SSID (Service Set Identifier) of your device to something besides the default setting. The default SSID ("linksys" for Linksys, "NETGEAR" for Netgear, "default" for D-link) is often a dead giveaway for unprotected networks.

In addition to changing your SSID and setting up a WPA key, be sure to change the default administrator password for your router. Most routers today come with no password for the administrator by default. If you don't change your administrator password, it may be possible for someone to set up your wireless router to block you from using it (though there would be very little personal benefit for the hacker for doing this).

What if I forget my administrator password?

All is not lost. Your router should have a "reset" button that you can press (maybe using a ball point pen) to restore your router to the factory default settings. From there, you can recreate all the security settings on your router. Also, check the web-based interface for a setting to backup or restore a file containing the settings of your router. You can use this to back up your router once you've set all your security features up, and restore it in case of failure.