OReilly windows XP hacks 100 industrial strength tips and tools aug 2003 ISBN 0596005113

If you have more than one PC at home, the best way to hookthem together and share a high-speed Internet connection isvia a wireless networkin particular, one based on the WiFi standard,

Network

The efficiency and throughput of WiFi networks can vary dramatically Make sure you get maximum throughput from your wireless network.

If you have more than one PC at home, the best way to hookthem together and share a high-speed Internet connection isvia a wireless networkin particular, one based on the WiFi

standard, which is actually a family of standards known underthe umbrella term of 802.11x

The biggest problem in setting up a home network usually

involves running the wires between PCs and a residential

gateway If your PCs are on different floors of the house, youmay have to drill holes in your walls, ceiling, and floors and runwire through Even when PCs are on the same floor, you have todeal with the problem of wires snaking along the floor

That's the problem I've had in my 150-year-old home in

Cambridge Drill through a wall, ceiling, or floor here, and younever know what you'll find (horsehair insulation was only one

of our many surprises) Even my electrician shudders when hehas to take out the drill

So, for me, a wireless network was a no-brainer I now have gothalf-a-dozen PCs and laptops and three printers in remote parts

of the house from each other, all connected via a combinationwired/wireless network and sharing a single broadband Internetconnection And when the weather is nice here (twice a year, by

my last calculation), I take my laptop out on my back porch andwork from there while still connected to the Internet and other

But there's a catch with all wireless networks, including mine.Wireless networks rarely deliver data at their rated bandwidthspeed One factor affecting bandwidth speed is the distancebetween the access point and the wirelessly equipped PC

Compaq, for example, notes that at a distance of 150 feet thethroughput of its wireless access point drops from 11 Mbps to5.5 Mbps, and at a distance of 300 feet it drops to 2 Mbps Eventhat significantly understates the drop-off in speed, and mostpeople find that the drop-off is much more dramatic than that,most commonly by a factor of two

Centrally locate your wireless access point This way,

it's most likely that all of your wirelessly equipped PCs willget reasonable throughput If you put it in one corner of thehouse, nearby PCs may get high throughput, but

throughput for others may drop significantly

Orient your access point's antennas vertically As a

general rule, transmission will be better when antennas arevertical rather than horizontal Keep in mind, though, thatthis is only a starting point for positioning its antenna Theexact layout of your house may alter the best positioning of

Point the antennas of your wireless PCs toward the access point Although 802.11 technology does not require

a direct line of sight, pointing them in this way tends to

increase signal strength USB wireless cards generally havesmall antennas that can be positioned, but frequently

wireless PC cards don't, so you may have trouble figuringout the antenna orientation in a wireless PC card If youhave a wireless PC card that doesn't have what appears to

Avoid putting your access point or PCs near

microwave ovens or cordless phones Many microwave

ovens and cordless phones operate in the same 2.4 GHzpart of the spectrum as 802.11b WiFi equipment So,

microwave ovens and cordless phones can cause significantinterference Cordless phones tend to be the bigger

problem

Avoid placing the antennas of access points or PCs near filing cabinets and other large metal objects.

then attach that wire to an antenna (For information aboutbuilding your own antenna, see [Hack #42]) Some accesspoints often accept booster antennas that you can buy aswell

If you have a Linksys wireless network and are looking to improve its signal strength, you can buy a $99 add-in that promises to extend its range and strengthen its signal The WSB24 Wireless Signal Booster sits on top of your existing wireless router You take the antennas off your router, attach them to the booster, then attach the booster to the router via cables I haven't tried it myself, so I can't personally vouch for it, but those who have tried claim it works.

Try and try again The ultimate way to find the best

placement for your access point and wireless PCs is to

continuously experiment and see what kind of throughputyou get Each house and office is so different that no singleconfiguration can suit them all

Carefully monitor your throughput as you make these changes,

so that you determine the best positioning for your access pointand PCs To determine your true throughput, use the free

network analysis program QCheck [Hack #57]

5.15.1 See Also

[Hack #42]

[Hack #57]

WiFi networks are everywhere, it seems; you can get free Internet access on wireless community FreeNets armed with your laptop, a car, and software called Network

Now you can bring your email to Starbucks

There are frequently dozens near one another, particularly incertain urban neighborhoods and suburban office parks thathouse high-tech companies Where I livein Porter Square in

Cambridge, Massachusettsthere are dozens of wireless

networks in private homes, apartment buildings, and businesseswithin a very short walk from my home There are at least half-a-dozen on my three-block street alone, in addition to mine.From my back porch, I get access to my own wireless network,but can also often pick up signals from four nearby WiFi

networks

The widespread availability of these inexpensive WiFi networkshas led to a grassroots community wireless networking

movement The idea is simple: allow people passing by to useyour WiFi network to hop onto the Internet and they in turn letyou and others use their WiFi networks for Internet access

when you pass near their homes or places of business Thesewireless grassroots organizations are often called FreeNets

You'll find them in cities including New York, Seattle, Houston,

Networks.org (http://www.freenetworks.org) In fact, some

cities themselves are creating free wireless zones in downtownbusiness areas to allow anyone with a wireless-enabled

computer to get Internet access Paris, for example, may soon

be known for more than its beauty, culture, good food and

disdain for tourists; it may turn into one giant wireless zone,allowing Internet access anywhere in the city, though for a

price

How do you find these wireless networks? The best way is by

doing what has become known as war drivingdriving through

neighborhoods with your laptop, special software, and, if youwant to pick up more networks, an antenna hooked up to yourWiFi card

The extremely environmentally conscious prefer to go war walking,

though walking around with a laptop is not particularly easy A better way is with a WiFi-equipped PDA, like the Palm Tungsten C.

Run the software, and it not only locates the network, but alsoprovides a variety of information about it that you can use toconnect to it, such as its SSID (network name), whether it usesencryption, and the wireless channel it's on Armed with thatinformation, you should be able to connect to it if it's a

FreeNetfor example, if it is set to allow anyone to connect to it,

or if it uses a commonly agreed-upon security scheme that

everyone in the FreeNet uses for their WiFi networks

If you walk in certain urban neighborhoods, you may notice strange symbols on the sidewalk that look something like those pictured in

Figure 5-1 Yes, it's a conspiracy, but in the positive sense These are

war chalking symbols that tell passersby that there is a nearby WiFi

network The left symbol means the wireless network is open; the middle one means it is closed; and the right one means it uses WEP encryption There may be other information next to the symbol that

gives information on how to connect to the network, such as the SSID The symbols were inspired by the practice of hoboes, who during the Great Depression would make chalk marks near homes that were friendly to hoboes and would give them food For more information about war chalking, go to http://www.warchalking.org

Figure 5-1 War chalking symbols

To go war driving, download the free Network Stumbler

program (http://www.netstumbler.com), which shows you

detailed information about any nearby wireless network Figure5-2 shows what happens when I run the software on my backporch I can detect signals from four nearby WiFi networks inaddition to my own

Figure 5-2 Detecting nearby wireless networks

with Network Stumbler

For each WiFi network it uncovers, Network Stumbler tells you

encryption is enabled, among other details Armed with thatinformation, you can try to connect to the network

If a network uses encryption, a small lock appears next to it; look closely at the Mookieville network in Figure 5-2 and you might be able

to see it.

Once you've found a network, exit Network Stumbler Then, toconnect to the network, double-click on the small network icon

in the System Tray (officially known as the XP Notification

Areathe area of the Taskbar where XP corrals little icons) TheWireless Network Connection Status screen appears (To seewhat it looks like, flip ahead to Figure 5-26.) From this screen,choose Properties Wireless Networks, and you'll see thescreen shown in Figure 5-3

Figure 5-3 The Wireless Network Connection

Properties screen

Network Stumbler, click Refresh If the network still doesn'tshow up, that's because the signal is too weak for you to

connect to it To connect to a network shown on this screen,click Configure and fill out the information required in the

screen You'll then get into the network

Not everyone will be able to use Network Stumbler, because itwon't work with all wireless network cards As of this writing, itworked with the following cards (and possibly some others notlisted here as well): Lucent Technologies WaveLAN/IEEE (AgereORiNOCO); Dell TrueMobile 1150 Series (PCMCIA and mini-PCI); Avaya Wireless PC Card; Toshiba Wireless LAN Card

(PCMCIA and built-in); Compaq WL110; Cabletron/EnterasysRoamabout; Elsa Airlancer MC-11; ARtem ComCard 11Mbps;IBM High Rate Wireless LAN PC Card; and 1stWave 1ST-PC-DSS11IS, DSS11IG, DSS11ES, and DSS11EG For more

information, go to C:\Program Files\Network

Stumbler\readme.html, assuming you've installed the program

in C:\Program Files\Network Stumbler.

outside of their homes or businesses can tap into their network.Some law enforcement officials will tell you that tapping intothose people's networks is illegal, so be forewarned

5.2.1 Mapping Wireless Networks

Network Stumbler lets you save your war-driving information in

a file, and you can then upload that information to a web site(such as http://wifimaps.com) that uses your information andinformation provided by many other war-drivers to create maps

of WiFi networks across the country You can zoom in and out

on these maps, so you can get a view of the concentration ofWiFi networks in a metropolitan area, or you can see individualWiFi networks on individual streets, as shown in Figure 5-4

Figure 5-4 A map showing WiFi networks in my

Somerville neighborhood

volunteer effort, and, not uncommonly, you'll find that the mapsaren't working If that happens, check back again in a few days;

it usually gets up and running after a while

5.2.2 Build a Homemade Wireless Cantenna for War Driving

One way to increase the range of your war driving and the

strength of the signal when you connect to WiFi networks is tobuild your own wireless antenna You can build them for a fewdollars using a tin can and other stray parts, as long as you'rewilling to do a little bit of soldering Because they're built out of

tin cans, they're frequently called cantennas.

My 13-year-old son Gabe built several for his seventh-gradescience fair project and compared the effectiveness of each Theresults were clear: the giant 34.5-ounce coffee cans were farsuperior to normal-sized coffee cans and Pringle's cans

If you haven't bought a WiFi card yet and are considering

building one of these cantennas, I suggest buying an Orinococard It has a small connector in its side through which you

connect a pigtail connector , which can then be hooked up to a

small antenna you build out of copper wire and a small

connector, which goes inside the tin can There are a number ofplaces you can buy a pigtail and the required connectors,

including Hyperlink Technologies

(http://www.hyperlinktech.com) If you don't have a WiFi cardwith a small connector, building one of these cantennas

becomes much more difficult

There are many places online where you can find good

directions for making cantennas Three good places to start are

www.oreillynet.com/cs/weblog/view/wlg/448,

www.turnpoint.net/wireless/cantennahowto.html Just so youget the idea of what you'll do, though, you first empty and washthe can Next, you build the small antenna that will go insidethe coffee can by soldering a short piece of thick copper wire to

a small piece of hardware called an N connector Then, drill a

hole in the can and insert the small antenna you just soldered.Attach the antenna to the can by securing it with small screwsand bolts Attach one end of the pigtail to your wireless card,attach the other end to the N connector, and voila! You have acantenna

5.2.3 See Also

[Hack #57]

[Hack #53]

Hack 57 Check WiFi Network Performance with QCheck to Help Improve Throughput

XP can't tell you the true throughput or your wired or wireless network For that, you'll need free, third-party software that can help you improve throughput.

When you buy network hardware, including a hub/router andnetwork cards, you're told that hardware's rated speedfor

a dramatic difference in the actual speed of your network So,you'll want to know the true connection speed of your network,WiFi networks in particular, so that you can optimize their

performance when you troubleshoot them

But how can you find out your true network performance? Ifyou have a WiFi card, you can find information about your

inaccurate True, its little green bars and Signal Strength

indication give you a broad picture of the relative strength ofyour network connection But the Speed indication isn't an

actual measurement as far as I can tell; it appears to tell youonly your maximum theoretical connection speed, given thenature of your hardware, and doesn't reflect your true currentconnection speed When I use my WiFi network, it always tells

me the speed is 11 Mbps, even when actual, real-time

measurement shows my true throughput is less than half ofthat

So, how do you measure the true speed of a network in yourreal-world conditions? Get NetIQ's free QCheck

(http://www.netiq.com/qcheck/) It performs a series of tests,including throughput and response time, and gives you a goodsnapshot of your network's real performance When trying tooptimize a WiFi network, run QCheck on each PC on the

network to get baseline performance results for each Then runthe test for each PC after you move the base station and PCs,change the positioning of the antennas, and so forth, as

outlined in [Hack #55] That way, you'll be able to fine-tuneyour network for optimum efficiency

Once installed on every machine in your network, QCheck

endpoint, which runs invisibly in the background on each PC onwhich you've installed QCheck While the exact metrics varyfrom test to test, the program works by sending data from one

PC to another on your network The data is then sent from thereceiving PC back to the originating PC, and QCheck measuresthe round-trip time, calculates throughput, and displays theresults

Figure 5-27 The QCheck console

Note the throughput in Figure 5-27; it's 5.128 Mbps I wasmeasuring the speed of my WiFi network whie seated on mybackyard porch, which is about 30 feet and a wall away from

reported my speed as 11 Mbpsthe exact connection speed mylaptop would have if I were inches away from the wireless

access point (And in actuality, the connection speed of a WiFinetwork, even when devices are next to one another, is wellunder 11 Mbps.)

To run the QCheck tests, run the console and then choose thetwo PCs between which you want to measure speed on yournetwork Only one must be the PC with the console on it, buteach PC does have to have QCheck on it You don't need to runthe console on each machine, because the endpoints are

running on them invisibly in the background; during QCheck'sinstallation the endpoints launch on startup

You'll need to know the IP addresses of the PCs you want totest If one of the PCs you're testing is the one running the

console, choose localhost for that endpoint To find the IP

click on My Network places, then double-click on your networkconnection (it might read Local Area Connection, for example,

address of other PCs on your network, first go to that PC, right-or Wireless Network Connection) Click on the Support tab, andyou'll see your IP address

Once you choose the PCs you want to test, choose the specifictest to run The best overall benchmark will be the Throughputtest using either the TCP or UDP protocols If you happen to useIPX or SPX on your network (some people still use these olderprotocols rather than TCP/IP), you can do benchmark

throughput tests using them as well, though few home

networks use those protocols If you run any kind of streamingmedia across your networkfor example, if you will be using yournetwork to play MP3 files or other digital music on a PC andthen stream it to another location in your housechoose the UDPstreaming test Streaming media use the UDP protocol, so theonly way to test how they will perform on your network is touse the test for that protocol

throughput from one moment to the next For example, a fewminutes after running the throughput test shown in Figure 5-27,

I ran it again and was shown a throughput of 1.602 Mbps Thatone test was an anomaly, and other tests were more in keepingwith my initial ones

5.17.1 See Also

[Hack #42]

Hack 53 Troubleshooting Network Connections with netsh, netstat, and ipconfig

More command-line tools for tracking down problems with your network connection.

netsh is a wide-ranging command-line diagnostic tool that has

an exceedingly large number of commands available (For acomplete list of available commands, use Windows XP Help andSupport and search for netsh.) Here you'll learn the most

interesting

Perhaps the most useful of the netsh commands are the netshdiag commands Use them to find out information about yourPC's network setup, such as finding the IP address of its mailserver, newsgroup server, DNS server, and similar resources

There are two ways to use netsh: directly from the commandline with all its switches, or first getting to the netsh console bytyping netsh at the command line and then typing the

command from the netsh> prompt that appears For example,you could type netsh diag show adapter at the commandline, which lists every network adapter on your PC, or you could

Use the netsh command to connect to the resources and thenget information about them For example, to find out the IPaddress of your DNS servers, type netsh diag show dns; tofind out the IP address of your mail server, type netsh diagconnect mail

Table 5-7 list the most useful of the netsh diag commands.Precede each of them with netsh diag Note that they eachhave many switches associated with them For more details,use Windows XP Help and Support and search for netsh

command prompt, type netstat It lists all connections,

interval value Run netstat repeatedly, pausing value seconds between each new

Description : WAN (PPP/SLIP) Interface Physical Address : 00-53-45-00-00-00

/setclassid "adapter" newclassid Resets the DHCP Class ID for the specified adapter.

/showclassid "adapter" Displays the DHCP Class ID for the specified adapter.

Hack 44 Tweak DNS Settings for Faster Internet Access

A handful of DNS hacks for speeding up access to web sites.

You use the Web by typing in hostnames such as

www.oreilly.com, but web servers and Internet routers can'tunderstand plain English words, so they need those letters

translated into numeric IP addresses Whenever you type in ahostname, such as www.oreilly.com, it needs to be resolved toits IP address, such as 208.201.239.37 DNS servers providethat name resolution automatically and behind the scenes asyou surf the Web

There are several ways you can hack your DNS settings so thatyou can get faster web access

5.4.1 Speed Up Web Access with a HOSTS File

It takes time to send your request to a DNS server, have theserver look up the proper IP address to resolve the name, andthen send the IP address back to your PC You can eliminate

visiting a web site The HOSTS file is a plain text file you can

create or edit with a text editor like Notepad