Linux Unwired 184
Linux Unwired: A Complete Guide to Wireless Configuration | |
author | Roger Weeks, Edd Dumbill, Brian Jepson |
pages | 300 |
publisher | OReilly |
rating | 8 |
reviewer | Alex Moskalyuk |
ISBN | 0596005830 |
summary | Complete guide to wireless configuration on Linux |
Infrared, Bluetooth, 802.11 (in current a, b and g offerings, 802.11i is also being discussed), wireless access points friendly to Linux, United States commercial cellular networks and GPS systems are all covered in a single title that surprisingly fits all of this information into 284 pages. All the chapters can be subdivided into two large parts - familiarizing yourself with the technology (the primer on GPS is pretty good) and running Linux on it (with code and shell command samples and lots of URLs).
Introduction
The authors start up with introduction to wireless, intended for Linux geeks who are not quite up to speed on radio technologies. The concepts of waves, spectrum and radio wave behavior are explained, so later the reader can explain what a retracted radio wave is. Then the first chapter moves on to explain antenna behavior, wireless infrastructure modes and some common problem, like a hidden node in ad-hoc infrastructure. The chapter is well-written, and you're not expected to have an advanced radio degree or ARRL membership to understand the terms.
WiFi cards
Chapters 2, 3 and 4 deal with connecting a Linux desktop or notebook to a wireless 802.11 network. The first issue is that of chipsets used in the wireless card, and even though enough research has been done already, authors discuss different quirks relevant to Intersil Prism, Lucent WavelLan/Orinoco, Aironet/Cisco, Symbol, Atmel, Atheros and Broadcom chipsets. We need to discuss chipsets instead of discussing the actual wireless cards, since some hardware may be shipped under the same brand name with different internals. "A good case in point: the D-Link DWL-650. This radio card initially shipped with a Prism II chipset and was very popular, because it worked on a Linux box. However, D-Link changed chipsets when it released the DWL-650 Version 2, choosing the ADMtek chipset. It is very difficult to tell from the packaging which version of the DWL-650 you are purchasing".
The chapters are done in traditional walk-through mode. They are not HOWTOs or compendia of reference information, available from the manufacturer's Web sites. The authors made an effort to ensure the reader is capable of starting up a wireless connection on Linux box, knowing nothing about it while learning important technology in the process. Certain wireless drivers need to be compiled into Linux kernel, so the task is not for the meek, but with detailed explanation, plenty of URLs and nice fonts and paragraph formatting O'Reilly Publishing uses to differentiate between the text, commands entered at the shell, and URLs, the book is easy to read.
Chapter 3 (available in PDF) teaches the reader how to connect to existing wireless network once the wireless card has been recognized by the system and proven functional. By the time the book hit the stores it was already a bit out of date, since the very first hotspot operator, Cometa Networks, shut down in May 2004. Chapter 4 discusses wireless security, touching WEP settings, a $20 Linuxant utility allowing the user to implement WiFi Protected Access, as well as authentication utilities wpa_supplicant and XSupplicant.
WiFi access points
The issue of WiFi access points is not trivial either, as many vendors out there will ship the product with a Windows app being the only way to set it up. However, for the access point setups that are Web-based, a browser in Linux will do the job. The most Linux-friendly access point include Linksys, Netgear, D-Link, Cisco, SMC, EnGenius, Belkin, US Robotics, Microsoft and ActionTec. Again, harsh reality kicked in between the time the book was written and went to press, and it's sad to see yet another Linux-friendly access point vendor quitting the market.
Not satisfied with commercial offerings out there? Chapter 6 takes the reader into the task of building your own access point. Don't forget that an access point doesn't need to be a compact portable - your old 486 with Linux on it and a wireless card connected to it might serve the purpose. Unfortunately, after all the hardware is bought and assembled, the final product might still cost you the quadruple (in case you go with smaller form-factor motherboards and CompactFlash cards for software storage), so consider this more as a geek project, not a viable solution. The authors use LinuxAP distribution for this task.
16 pages are dedicated to hacking Linksys WRT54G access point with Sveasoft, described as disruptive technology by Robert X. Cringely. The authors also take a brief look at Wifi-box and OpenWRT.
Other wireless technologies
Bluetooth, Infrared, cellular and GPS chapters follow the same chapter plan - first the basics of the technology and simple use case scenarios of what you might use it for, then the hardware needed to implement the wireless technology, available Linux software to do the jobs, accompanied with the list of shell commands to successfully talk to a wireless product, and after that typical applications of the working link.
The authors tested various wireless data plans in the United States, although this data, once again, is constantly changing as the operators buy one another and introduce new data plans. The winner of the quality and the fastest download tests, by the way, was a Motorola v120e phone on Verizon Wireless network. In upload speed tests a Merlin C201 PCMCIA card on Sprint PCS network won. T-Mobile also offers a PCMCIA card for its GPRS network, so the authors install and run it under Linux in Chapter 9.
The last chapter discusses using Linux computers with GPS devices and open-source GPSdrive project for reading GPS data.
The book
For those just venturing into the wireless world, the book would be useful. All the information provided on WiFi connectivity can perhaps be googled and found in various HOWTOs. With wireless operators, GPS systems and Infrared connection one would have to rely on enthusiast sites and newsgroups. Having such informative title that covers all of the technologies would be very useful to a Linux enthusiast.
With that, the book can be quite overwhelming, although it's probably not intended to be read from page 1 to the end. There's usually more than one correct way to do things in Linux, and for each successful project another competitor appears on SourceForge the next day. I like the authors' approach of dedicating most of the chapter space to one, leading, Linux package that seems to be dominant in the field, and then briefly mentioning the others. A notable omission is Intel's Centrino drivers for Linux, as the company is bound to become a leader in the chipset marketplace with 42% of notebooks shipped in 2003 running Centrino chipsets.
But overall the book proved to have a high informational and educational value, not only you follow the steps on setting up wireless technologies on Linux, but you also learn the internals of the technology and why certain things are done that way, but not another.
You can purchase Linux Unwired from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, carefully read the book review guidelines, then visit the submission page.
Easy solution (Score:3, Insightful)
Re:Easy solution (Score:1)
Re:Easy solution (Score:1)
Re:Easy solution (Score:1)
Re:Easy solution (Score:1)
Re:Easy solution (Score:2, Informative)
Beat that, Carnack! (Score:1)
Re:Easy solution (Score:1)
Re:Easy solution (Score:2)
Heh. The only time I ever had a problem with the wireless zero service was on an airport. (I doubt that was the problem, though...)
Re:AirMac (Score:2)
That's a genuine problem (Score:4, Informative)
Microsoft disputes the notion that there's a problem with the way Windows XP works with Wi-Fi.
That's a blatant lie, typical Microsoft attitude.
For the longest time, the wi-fi connection of my notebook would keep dropping and I thought it was because of a bad wireless card.
I changed my wireless card, I tried everything possible.
What I had not noticed was everything I was in Linux, this never happened - no matter what! There are areas in my school where the wi-fi signal strength is particularly weak, and even in those areas I never lost connection from Linux.
Somehow, when I would boot into Windows, my wi-fi link would keep dropping. I still haven't figured the problem yet, I just use Linux instead everytime.
And so contrary to what Microsoft may say, there is a problem with Windows XP (I have the problem whether am on XP Home or XP Pro). I wonder whether they EVER admit their mistakes.
Re:That's a genuine problem (Score:3, Informative)
At the very end of the article they state that you can bring the connection back to life by stopping and starting XP's Wireless Zero Configuration service -- I wish I had known that during some very ill-timed outages! This suggests that XP has everything to do with the problem but I'd still be careful in blaming Microsoft outright. Still, what a disaster.
I wonder now if
Re:That's a genuine problem (Score:4, Informative)
Yes you can. The Intel PROSet driver works far better when compared to the zero config. Set up a list of preferred APs and the PROSet tools will connect in order of preference and NOT continue to bump you around to other APs when they show up as long as any on your preferences are available. If you wan't I beleive you can even turn that off and go for a fully static config.
HTH,
-nB
Re:That's a genuine problem (Score:2)
If I can't recreate and experience the problem, I can't fix it. Microsoft has heard these complaints, and has probably investigated the problem; if they can't experience the problem on their own, the logical conclusion is that it's not on their side. Of course, with something as complex as an OS and the associated software, hardware, drivers, etc. for the wirelesss, it's much harder to track down a bug, let alone find the exact settings that cause it.
Re:That's a genuine problem (Score:4, Informative)
Re:That's a genuine problem (Score:2)
Re:That's a genuine problem (Score:2)
Yes, it is clear cut.
Re:That's a genuine problem (Score:5, Informative)
Good Luck
JFMILLER
SSID rebroadcast is NOT a solution (Score:4, Interesting)
It is unacceptable to be disconnected, even if you are immediately reconnected. This is the situation of one of my clients.
His PC bounces while his two laptops, both on the same desk, all of which are no more than 5 feet without obstruction from the wireless router, never have a problem.
Plus his PC didn't always do that. And changing router frequency channels doesn't solve it.
Dumping the MS config and moving to a manufacturer connector is the only solution for hosed XP machines like this.
Re:SSID rebroadcast is NOT a solution (Score:2)
Re:That's a genuine problem (Score:3, Informative)
I could have told you that! *grins* WinXP's utility is useless. On a lot of systems, I couldn't get it to hook up to a router of the same brand 2 feet away with the default settings. I tell Microsoft what it can do with it's utility, install the one from the manufacturer, and BAM, it works.
I should have known better than to trust software from Microsoft over the software from the manufacturer.
Re:That's a genuine problem (Score:2)
I recently migrated from a 10/100 wired home network to a wi-fi network. For the first two weeks there was no problem whatsoever. I had read about the problem with XP seemingly dropping the wi-fi connection, but I had never experienced it.
Last night, I set up a couple of shared folders on each of two different computers on the network (using a wi-fi router connected to a cable modem), and this problem appeared. The wireless connection would dr
WPA was the source of my woes (Score:3, Informative)
Eventually after one night's worth of Windows's Eventlog data, when I forgot to switch my laptop off, I realised that there was almost precisely an hour between disconnections. An alarm bell rang in my head because o
Re:WPA was the source of my woes (Score:2)
Re:Question? (Score:2)
It's just that if you had any problems setting it up in Linux, they will not help you (they == tech support). You will have to figure things out yourself, that's all.
Atleast that's how it is in other institutions which have similar rules in place.
Windows Wireless Zero Configuration Problem (Score:5, Informative)
The problem is if Windows can find a network that broadcasts it's SSID when yours doesn't, it will try to switch. There are three (or four) soltuions.
I REALLY hope that they fix this in SP2, because it's my number one complaint.
Re:Windows Wireless Zero Configuration Problem (Score:2)
I first encountered it yesterday, when a friend of mine installed a Linksys WUSB11 and complained about the drops. His network did not broadcast the SSID... and there are no other SSIDs being broadcast (that he can detect).
This is the first I've heard of this problem... but I've been configuring and using wireless networks for myself and friends for almost two years.
Re:Windows Wireless Zero Configuration Problem (Score:2, Informative)
Re:Windows Wireless Zero Configuration Problem (Score:2)
Re:Windows Wireless Zero Configuration Problem (Score:2)
Re:Windows Wireless Zero Configuration Problem (Score:2)
There doesn't seem to be any rhyme or reason why the problem occurs. No configuraiton changes, no changes in wireless networks (mine or anyone else), etc. It just start
Is it just me... (Score:4, Insightful)
Don't get me wrong, I'm not a luddite and I think these are great technologies, but for myself they just seem expensive and not terribly useful. What I do find interesting is use of WiFi for rural broadband. But that's still pretty novel.
Re:Is it just me... (Score:3, Funny)
Re:Is it just me... (Score:1)
Re:Is it just me... (Score:2)
Re:Is it just me... (Score:2)
Re:Is it just me... (Score:2)
I don't see what cell phones have to do w/this but anyway... Yeah, I guess that wlan's aren
Re:Is it just me... (Score:1)
Oddly enough, in certain respects, wires can play an effective stategic part in this strategy.
KFG
Re:Is it just me... (Score:2)
Uhhhhh, maybe because it is a wireless device? Just guessing. . .
Re:Is it just me... (Score:1)
I don't see the appeal of wireless on a home LAN either. But Wireless starts to look useful, when you're travelling.
Wait a minute .. you mean using someone else's computer? That is a security problem. How do you know it's no
Re:Is it just me... (Score:2)
Re:Is it just me... (Score:2)
Re:Is it just me... (Score:1)
A wonderful side benifit is that I can place my systems anywhere and am not contrained to walls that have poth power and a network tap. LAN parties are so
Re:Is it just me... (Score:1)
I don't see the appeal of wireless on a home LAN either.
Actually wireless is exceptionally useful in the home.
I live in an appartment and I have no control over where the phone comes in. Now, rather than having a very long phone line strung across the floor or ceiling I put my DSL modem on a wireless bridge to my router/AP. (I know I'm going to get slammed for this security wise, but I have taken some steps to harden the link.)
Furthermore I use the same wireless AP to move ethernet availability to my
Re:Is it just me... (Score:2)
I like the security that comes with a wired network, and my company does too, seeing how it is policy to keep the wireless hardware disabled.
I think WiFi has it's place, just not with me.
Re:Is it just me... (Score:5, Insightful)
I thought the same thing for a while... but after working on my laptop at home with no wires for the kids to yank on/trip over, I'll never go back. If I run across something interesting, I can carry my laptop in to another room to show my wife. If the living room gets too loud, I can move into the dining room. It's very handy.
And for some reason I still get a kick out of printing something over a wireless LAN connection. Just something odd about clicking the "print" button, with no wires attached, and then hearing my printer downstairs leap into action
Re:Is it just me... (Score:2)
Glad I'm not the only one overly fascinated by printing on the Wlan.. somehow, causing an effect in the real world really makes one appreciate the wireless connection. (another fun trick is to ssh into another machine and do something like $ eject /dev/cdrom && eject -t /dev/cdrom ;))
Re:Is it just me... (Score:2, Insightful)
I love being outside by the pool and taking care of a backlog of emails or simply using my Mod points.
But speaking of printing; we have an upstairs game room thats my wife's office. My office is directly below hers. Anyway, the cats LOVE to lay on her desk and look out the window at the trees.
I get a HUGE ki
Re:Is it just me... (Score:3, Insightful)
Re:Is it just me... (Score:2)
Not in my view, no. My laptop floats between home and work. I have wireless at both home and work. I have long battery life on my laptop. At either place, I just pull it out and turn it on. It doesn't seem like much, but it's actually kind of a pain in the butt to go hook up ethernet/power cables. The convenience factor is there, not to mention that I can clear out of a room quickly.
Additionally, I had a PocketPC for a short time. I *really* enjoyed having t
Re:Is it just me... (Score:4, Interesting)
It all depends on your needs or work habits. Here are my personal reasons:
Re:Is it just me... (Score:1)
I've been using Wireless services for a few years now, am a big user of WLAN, had the first Ricochet modem setup in my area when it was released, etc. I've been wirelessly connected to the 'net now for almost 10 years.
I have come to love WLAN. With my current setup, I can go sit in the park across the road, tiBook in hand, enjoy the outside fresh air and do my e-mail under a tree. After work I can drive up for a quick 'mail sweep' outside my front door, connect to my net with my sl5500, download my late
Re:Is it just me... (Score:2)
Absolutely (Score:2, Insightful)
Zuh? (Score:2)
Or in the floors in access panels?
That's how we do it here. We can move furniture, racks or equipment around, just replug the stuff in to whatever's closest. It's all on the same switch, so it's no big deal.
Renewed competion between broadband providers (Score:3, Interesting)
Besides user convenience, one of the benefits of wireless networks (particularly long-range wireless) is that they can compete directly with DSL, Cable modem, and landline phone service. My parents live out in the country on a hill about five miles from the nearest large town (McMinnville, OR). They have fast internet service thanks to a reasonably forward-looking ISP who set up a wireless network using radios from waverider [waverider.com]. Unfortunately, the waverider site doesn't list prices anymore (I believe they u
Re:Renewed competion between broadband providers (Score:2)
For instance, I take my notebook with me and I can access the net from my classrooms, cafeteria, park, conference rooms and just about any place.
And it sure as hell beats having to carry around a cable everywhere, and having to provide network access points all over the place.
I'm now at my internship, and a bunch of us in the apartment complex have pooled in and gotten a single Internet connection with a wireless router, so that the rest can access it.
And when I
Re:Is it just me... (Score:2)
I use both wired and wireless now. At work, I have a dock for my laptop that includes a PCI network card, the dock has three normal PCI slots.
At home, I just use the wireless card so I can use my laptop on my dining table or my lap in the living room rather than going to the den.
I have also set up an outdoor wireless sy
Re:Is it just me... (Score:2)
Linux and Wireless (Score:5, Interesting)
Re:Linux and Wireless (Score:2)
Not too hard, is it?
Re:Linux and Wireless (Score:2)
It gets worse than that: there were at least two major versions of the DWL-650 (excluding firmware revs), one with the fan-shaped antenna, and one with the square, similar to that found on the DWL-650+. Only th eone with the "fantenna" has the widely supported Prism chipset. The square one is currently available in BestBuy for $39.99 with a $20.00 mail-in rebate.
The "fantenna" ones are curre
Problems with DWL-G650 (Score:2)
Re:Problems with DWL-G650 (Score:2)
I got rid of all my D-Link equipment after about 2 weeks (it took 24 hours to return the PCMCIA card)
If you can get them to work in Linux, great job!
If you can get them to work in Windows, you got lucky!
I'd get LinkSys as I've had zero problems with their wireless equipment and perform very well. Cisco is another great choice if you can afford their hardware (3-4X the price of LinkSys)
DWL-650 (Score:5, Informative)
After going through many different drivers and kernel compiles, I Later found that some 650's not only have an ADMTek chipset but some also have be a Realtek chipset. After trying the ADMTek drivers I found my particular card had a Realtek chipset and it came right up using the ndiswrapper driver using the windows Realtek driver (the driver supplied by d-link on the cd would not work. I had to get the windows driver from Realteks site). The thing works like a champ now with Fedora core 1.
Re:DWL-650 (Score:2)
Why didn't you just spend the $40 or so for a card that is absolutely known to work with Linux instead of wasting a number of hours (over the course of a week)?
Re:DWL-650 (Score:2)
Yeah, but I don't consider having to use some other operating system's driver a "working" solution. What I meant to say is that if I were in your situation I would've bought a card with a native driver.
hate to say it, but if I just wanted it to work, I would have put windows on it.
That's exactly what I was driving at. It's good to hear that someone on Slashdot can be honest about the fact that stuff "just wo
Honesty In Advertising (Score:4, Interesting)
Re:Honesty In Advertising (Score:2)
Directions here:
http://www.tipsybottle.com/technology/wireless/
Ah, the bitter irony (Score:3, Insightful)
Since you are into security, perhaps you would be happy getting an STD? Security Tools Distribution [knoppix-std.org], that is. That livecd will likely have any tools on it you need as well as det
stab (Score:2)
Yes, you got me to ssh into my home media center.
Hope That Helps. Have A Nice Day.
Re:Honesty In Advertising (Score:2)
If you like it, you can do an image install easily with the included Knoppix install scripts and is easy to maintain with its Debian base.
Computer Book publisher's business plan (Score:2, Insightful)
2.) Paraphrase information freely available on the net.
3.) Blow college professors and get them to use it as a text book for their class!
5.) PROFIT!!
IPv6 (Score:2)
The one downside is that if your outside IPv
Mapping Wi-Fi under Linux (Score:2, Informative)
this fixed wireless for me w/XP.. (Score:2)
If your connection is dropping and you're not being asked to connect to another network, make sure that you have not checked the "Enable IEEE 802.1x authentication for this network" checkbox, as this can also cause problems (but was not the root cause of this issue).
---
I'm not sure what IEEE 802.1x authentication does exactly, but turning it off in XP made wireless stable. Before that I could be really close to the wireless hub and I would be rand
Broadcom support (Score:2)
Re:Broadcom support (Score:2)
Re:Broadcom support (Score:3, Interesting)
1. No 3rd party will write Linux drivers, nor will BCM, until there is a clear need from a profit standpoint. This is like trying to get major software vendors to make a port.
Power Save (Score:3, Interesting)
-foxxz
screw it, use driverloader (Score:3, Insightful)
I'm three days into the evaulation period and I'm giving them my $20 for the software. It's too easy this way to go the free/annoying route. 'Sides, at the amount of money I end up earning/hour, spending two hours of my life to get a wireless card working it costing me more that $20.
Re:screw it, use driverloader (Score:2)
Re:which are the best of the.... (Score:2)
I just wish manufacturers would stop radically changing the product without changing the model number, as wireless card manufacturers seem to like doing. It only adds to confusion.
That example seemed deliberate (Score:3, Insightful)
Since the book was about Linux, there was no real practical reason for including it. Is the book going to tell how to get around the XP problem?
No.
That's a lot of type to say simply "some wireless cards aren't supported by Linux out of the box".
Re:That example seemed deliberate (Score:2)
Re:That example seemed deliberate (Score:2)
Ignoring bugs in your products/your customers usually brings criticism. Had MS acknowledged the bug & explained a (working) way to avoid it or delivered a patch that fixes the problem they would not be criticized.
Given that MS has decided to exit the wireless access market they wont be leveraging the desktop for wireless products anyway.
personal experience with xp & wifi (Score:4, Interesting)
Another Windows XP wireless bug (Score:2)
One of them happens with WPA (which I do hope you are using, given that WEP is so easily hacked), and causes you to disconnect after a few minutes. After reconnecting there are no further problems.
This appears to be a working fix, needs a registry edit:
>> This will solve your WiFi problem! although this
>> should be considered a workaround,
>> rather than a fix. With AuthMode set to 2 it means
>> Ma
Brain Hurts (Score:4, Funny)
I swear it said something like "This book is not about what the title says it is about, except that three chapters actually are about that, but the rest isn't. But that stuff is related. Fuck Mocrosoft."
Oh, and somehow it lead into all that with a reference to sock puppets.
I might be wrong, but I am mortally afraid of re-reading the summary given the results of the first read.
Is the actual review any better?
-Peter
Best wireless card for linux? (Score:3, Interesting)
Re:Best wireless card for linux? (Score:2)
Indeed. (Score:2)
Re:Best wireless card for linux? (Score:2)
http://books.slashdot.org/comments.pl?sid=11129
Re:Best wireless card for linux? (Score:2)
SuSE 9.0 & Linksys WPC11 v3 on Dell Inspiron 3 (Score:2)
Boring story short: it works, but damn is the YaST screen is nasty and watch out for non-acpi compliant (read old) mobos.
Linux Wireless Zero-Configuration (Score:3, Interesting)
For added points, it should work with any wireless card and driver that is supported under Linux.
-allen
Re:noooo (Score:1, Offtopic)
The characters they portrayed, however, do not.
Maybe it is just a pet peeve of mine, but it drives me nuts when people get all uppity over someone elses use of language, and attack with even poorer use of the language.
Re:noooo (Score:2, Funny)
I don't need no instructions to know how to rock!!!!
I that case where would you like me to send your rocking instructions?
KFG
Re:If only USB adapters were supported... (Score:2)
Unfortunately, your WG121 is not among those, but the Linux Prism G [prism54.org]
Re:D-Link DWL-120+ (Score:2)