Introduction

Welcome to the irc.freenode.net/#wireless Frequently Asked Questions page. Look here first for resources and tips on doing your Wifi magic.

Other websites you should look at for help are:

http://www.hpl.hp.com/personal/Jean_Tourrilhes/Linux : The Linux WLAN Driver HowTo page
http://prism54.org/supported_cards.php : Linux support for Prism54 based 802.11a/g cards.
http://sourceforge.net/projects/madwifi/ : Linux support for Atheros based 802.11a/g cards.
http://www.mattfoster.clara.co.uk/madwifi-faq.htm : MADwifi FAQ
http://madwifiwiki.thewebhost.de/wiki/FrontPage : MADwifi wiki. Contains helpful 'user recipes'
http://hostap.epitest.fi/ : Linux support for Prism 2.0/2.5 802.11b cards.
http://linux.oldcrank.com/tips/wpc11 : Tips for setting up a Linksys WPC11 (or, get a real card).
http://nocat.net/faq.txt : The NoCat Wireless FAQ
[http://www.seattlewireless.net/index.cgi/HardwareComparison Hardware Comparison pages]
http://www.wifi.com.ar :
http://m0n0.ch/wall : An all in one firewall package.
http://www.wireless.navigator.co.uk : Tools and information.

Community Wireless Networks who hang out here.

http://www.manchesterwireless.net : The Manchester Wireless broadband project.
http://www.houstonwireless.org : The Houston Wireless User's group.
http://www.nycwireless.net : New York City Wireless - Hotspots for the pigeons/
http://www.seattlewireless.net : The Seattle Wireless User's group.
http://www.bcwireless.net : The BC Wireless Project.
http://www.personaltelco.net : The Personal Telco Proejct.
See also : WirelessCommunities

The Questions!

TableOfContents

General IRC Channel Questions

Who runs the channel

The #wireless channel is maintained by people from various wireless groups and walks of life. The rule of the channel is largely egalitarian in reflection of the openness of unlicensed radio spectrum and the spirit of many community wireless networks.

I asked a question but no one is answering me!!

Most of us have jobs away from chatting in IRC. If you asked a question but no one answered, it's likely because no one knows, or has the time to answer. Hang around for a while and someone might have an answer for you. Don't repost your question over and over though, it'll only serve to annoy other people in the channel.

Some asshole named 'aml' banned or kicked me. Wtf?

As part of a new initiative to return the signal to noise ratio of #wireless to something endurable, jackasses will now be kickbanned whenever 'aml' notices them. The criteria for jackassery include, but are certainly not limited to: describing your commercial activity with such vigor and repetitiousness it becomes a shill so shrill only dogs can hear it, answering questions pedantically and then immediately transitioning into shilling, asking stuff in the FAQ over and over again like a moron, etc. etc. In general, don't be stupid.
- AndrewWoods

Who is WifiFred?

WifiFred is our IRC Bot, he maintains a database of various Wireless and Internet related things like Cable types and Internet Standards. He also does simple calculations on Fresnel zones and Path Loss. For brief help, use !help .
See WifiFred for a complete command reference and additional information.

Are there channel archives?

Yup. IRC logs are kept [http://irc.bcwireless.net/logs/irc.freenode.net/%23wireless/ here] (as of Sep 15 2004).

Community Wireless Issues

Where can I find a Community Wireless Group to hook up with?

The WirelessCommunities page has a list of groups around the world.
The [http://wiki.freenetworks.org/index.cgi/WirelessNetworkingProjects FreeNetworks.org WirelessNetworkingProjects] page lists some more.
[http://www.nodedb.com/ NodeDB.com] lists community wireless nodes around the world.

Where can I find peering agreements for Community Wireless networks?

The original [http://www.picopeer.net/ PicoPeer] agreement
[http://www.freenetworks.org/peering.html FreeNetworks Peering Agreement]

Also check out the [http://lists.freenetworks.org/mailman/listinfo/community FreeNetworks community mailing list].

Where can I find an acceptable use policy for my community wireless hotspot?

See AcceptableUseDisscussion

Commercial (for-profit) Wireless Issues

How can I make money?

Q: I have a great idea on how to serve my local starbucks and makes loads of cash. How do I do it?
A: Go [http://isp-lists.isp-planet.com/isp-wireless/resources/how_to/ here] and don't bug us.

Why are WISPs so hostile to community wireless?

Not all are, but occasionally we run into the odd WISP who will spew fud about Community|Open Wireless Networks.

Just ignore them, they're nothing more than PissAnts.

General Linux Stuff

How do I install <blah> package?

Read [http://www.linux.com/article.pl?sid=03/11/26/1337210 this].

Are there any small linux distros with wireless?

Yes. [http://nycwireless.net/pebble/ Pebble Linux] has the latest wireless tools plus things like NoCatAuth built right in. It is a FreeNetworks project maintained by Terry Schmidt of NYCWireless. It is designed for [http://soekris.com/ single board computers], but can run on a laptop, old PC and other x86 based machines. Pebble is the default OS on the [http://metrix.net/metrix/products/packages/ Metrix Kits]

[http://leaf.sourceforge.net/ LEAF] is another small distribution that requires less space and has a menu interface, but has less advanced features.

Other: [http://www.cqure.net/tools.jsp?id=9 CQureAP (one floppy, kernel 2.6, hostap)], [http://sourceforge.net/projects/warlinux/ WarLinux (outdated)].

Wireless Network Card Questions

What is the best 802.11b wireless card?

This is a highly subjective question. It all really depends on what you are going to do with it.

Some say the best all around wireless card is an old Lucent/Orinoco Silver or a Gold card. They have good OS support, an internal as well as an external MC-Card antenna jack, and have one of the [http://wiki.freenetworks.org/index.cgi/ReceiveSensitivity highest receive sensitivities] on the cards in the 30mw-50mw range.

If you are looking for a high powered PCMCIA card, you may want to get a [http://metrix.net/metrix/products/radios/pcmcia 200mw Senao Card]. There are two models of card, one with an Internal Antenna only, or a card with 2 diversity (both listen to the wireless signal, and the antenna with the most signal wins) external MMCX antenna jacks. Senao cards are less flexible since there are two models, but the added power and excellent receive sensitivity make them a good choice for outdoor links as well as wardriving and monitoring applications.

If you are looking to make a machine act as an access point under linux, you really only have two options. HostAP and MadWifi. HostAP has been around longer and is considered stable, but because it is based around the Prism2 chipset, it lacks 802.11g and 802.11a support. Old hermes based chipsets (the old Orinoco cards) cannot act as an AP under linux without HermesAP which may get you in [http://hacks.oreilly.com/pub/h/860 hot water], and also you will miss out on a lot of the new stuff.

If you are going the HostAP route, you might want to look into the Zcomax Prism2Card or the Senao 200mW cards. An unofficial support page for [http://www.seattlewireless.net/index.cgi/SenaoCard SenaoCards] is maintained by SeattleWireless.

MadWifi is a relatively new driver (grab the CVS version), it works with Atheros based cards, allows you to act as an AP, do WDS as well as tap some of the more advanced parts of the wireless card. It seems to be the driver to get if you are into trying new things. You can get Orinoco branded PCMCIA cards as well as [http://metrix.net/metrix/products/radios/minipci MiniPCI Atheros Cards]

Will my D-link DWL-650+, 3Com USR2210 (or other TI chipset 22 Mbps hardware) work in Linux or *BSD?

Yes. There's the ACX100 project available at http://acx100.sourceforge.net , which managed to write an OSS driver despite
- not getting any chipset specs from TI, D-Link or USRobotics. Please tell TI, D-link et al. that real Linux support would be greatly appreciated. Note that similarly named cards usually will NOT work with this driver, due to D-Link's highly idiotic product naming policy.

Will my Broadcom chipset wireless card work in Linux or *BSD? (Linksys wmp11v2.7 and Dell Truemobile 1180 for example)

Maybe. [https://www.linuxant.com/driverloader/ Check here] for a Windows driver wrapper.

Will my Atmel chipset wireless card work in Linux or OS X? (SMC2632W)

Maybe, look at http://atmelwlandriver.sourceforge.net/news.html
There is an [http://www.russotto.net/~russotto/atmelx.html OS-X driver] available as well.
Linksys has published Atmel source code, available from ftp.linksys.com, specifically [ftp://ftp.linksys.com/pub/network/ATMEL_linux_drivers.tar.gz here]. If not, you're probably out of luck. Contact the manufacturer, and failing that, return the product.

Side Note - The SMC2632W has 3 Revsions the First Revsion marked by a fcc id of WL1100 is a Prism2 based card and will work with the prism2 drivers. The rev one will say WL1100-1 also it only has one orange colors light. This is the same unit as the US Robotics 2410 card.

I'd like to try doing ___________ with 802.11b. Will it work?

Dunno, maybe. Wireless networking depends on so many different factors that it's impossible to say for sure. Try it and let us know.

Do 802.11a cards work under Linux or *BSD?

There is a Linux driver for Atheros based cards available from http://team.vantronix.net/ar5k/ however this driver is experimental and may not work!
Note that some hardware combinations (such as the VIA EPIA board) may need IO address reservation, otherwise MadWifi won't find the card. example:
- For Atheros+Pebble+VIA-EPIA, add 'append="reserve=0xd3405fff,0x2000" ' to lilo.conf
An Atheros gifted driver is available in FreeBSD 5-CURRENT (aka: FreeBSD 5.2). See the [http://www.freebsd.org/cgi/man.cgi?query=ath&apropos=0&sektion=0&manpath=FreeBSD+5.1-current&format=html ath] man page for more details.
Linux drivers are available from the [http://sourceforge.net/projects/madwifi/ Mad Wifi] source forge project. If you have an unsupported chipset, contact the manufacturer, then return the hardware.

Do 802.11g cards work under Linux?

Apparently, some of them do. There is the [http://prism54.org/ prism54 project] and the [http://sourceforge.net/projects/madwifi/ madwifi project].
[http://returntonature.com/pipermail/linux-sony/2003-September/005565.html Here] is a mini-howto for getting a linksys dual band card to work using the madwifi driver.
If you are using the MadWiFi drivers and the card won't seem to associate with your Access Point, like my (solarce at fallingsnow.net) Netgear WG311 (a good buy, $60 shipped at newegg.com) was.
- Then just follow these easy step for Linux powered 802.11g bliss.
- 1.) (Assuming you've installed the madwifi drivers from cvs and loaded the 'ath_pci' driver) ifconfig ath0 up 2.) iwconfig ath0 ap xx:xx:xx:xx:xx:xx (this is the mac addy of your ap, you can probably find it with 'iwlist ath0 scan') 3.) iwconfig ath0 channel XX (1-11, whatever your wap is set to) 4.) iwconfig ath0 essid your_essid_here 5.) iwconfig ath0 rate XXMB (your rate here, i.e. 11MB, 54MB) 6.) ifconfig ath0 x.x.x.x OR dhcpcd/dhclient/pump ath0 (for dhcp goodness) 7.) Let Cool and Sprinkle with Powdered Sugar (ok not really)
  And now you have 802.11g under Linux, me, I am using the card in my shiny new xp 2700+ powered MythTV machine, (http://www.mythtv.org) Enjoy!

I'm trying to use my ________ (prism2 chipset card) under linux, and I can't figure out wlan-ng, help!

You might want to try using HostAp ( http://hostap.epitest.fi/ ), it is a driver that supports ad-hoc, infastructure and master modes, and uses the linux wireless extensions, so you can configure it with iwconfig, unlike wlan-ng.

What driver should I use for Linux?

For lucent/orinoco cards, orinoco_cs, for Prism2/2.5/3 HostAp is strongly suggested, for cisco/aironet cards, airo_cs. You can get rpms of kernels including hostap at http://www.cat.pdx.edu/~baera/redhat_hostap/ These are using the redhat patched kernel source, with hostap included.
<coderman> Chalain : choosing wlan-ng over hostap is like a child accepting a ride fromBR a strange man offering candy with one hand down his pants

How do I get my Linksys WPC11 to work under Linux?

See http://tldp.org/HOWTO/mini/Wireless-Link-sys-WPC11/
I do not recommend following these directions, as the drivers are not totally compatible with the linux wireless extensions, which are a standard all the other drivers follow. If you choose to use wlan-ng, please don't expect any support what so ever from #wireless. The WPC11 is a prism2 chipset card, try following directions for other prism2 based cards, orinoco_cs and hostap will also work, and both support the linux wireless extensions. --ForrestEnglish

How can I find out what chipset my network card uses?

One way is to find the FCCID for the card (usually on the card itself) and search the FCC's database: http://www.fcc.gov/oet/fccid/ Another is to check these lists that others have compiled:
http://seattlewireless.net/index.cgi/HardwareComparison : Covers most client adapters and APs, good notes on connector type, power, drivers and even price.
http://www.linux-wlan.org/docs/wlan_adapters.html.gz : Probably the most extensive out there, but lacks in helpful tips found on the previous list.

I want a wireless network scanner under Linux, or help configuring one, please?

For linux the best option is definitely [http://kismetwireless.net Kismet]. There is a [http://truffula.net/~forrest/kismetorinoco.shtml guide] to setting up kismet 2.8 using linux 2.4.20 and an orinoco wireless card here. Kismet supports prism2 and cisco cards as well (cisco cards, and prism2 using hostap don't require any kernel patches, just follow the directions in the kismet readme files).

Will my USB wireless adapter work under Linux?

Maybe, support is iffy at best right now. If you are using a prism2 usb adapter, I wish you luck with wlan-ng. If you are using somthing else... I wish you a short trip back to the store.

How can I find what version of Firmware my Wireless Network card has?

You can find out what firmware you are using by checking /var/log/syslog or /var/log/messages (depending on your distro) when you insert the card. This may or may not work I'm afraid, but you should definitly look.

I want to install some kind of authentication software for my wireless network, can I do that?

Most access points have mac address limiting options, and also you could enable WEP. Mac addresses can be faked however, and WEP can be broken fairly easily. If you just want to keep causual users off your network, WEP would be your easist solution, just check out the manual of your access point for instructions on enabling this. A better solution might be to use real authentication software like NoCatAuth.
You'll probably want to be comfortable with linux to do this, and use a linux machine as the router either using HostAp or with the access point hooked up directly to the machine. Then you'll want to checkout http://nocat.net for authentication gateway software called NoCatAuth.

Antennas and stuff

dB, dBm, dBi, mW, W.... What is all this stuff?

mW stands for miliwatt, W for watt. Sometimes we talk about watts, but usually we talk about dBm, dB and dBi. Simply put, dBm is the amount of power your radio transmits. dBi is usually the amount of gain your antenna has. You can add dBm and dBi together to find out a rough idea of how much "power" the card and antenna will put out.
For an explanation on the dB stuff, check out the DeciBels page.

How can I calculate the distance my antenna will have?

It depends what you're transmitting through. First you need to know what your FreeSpaceLoss is. Assuming you have perfect LineOfSight, the FSL at 5 miles is 118.36 dB. At ten miles it's 124.38 dB. Then you do this:
```
 ( txdB + txdbi ) - fsl + ( rxdbi ) 

  where:
    txdB is the amount of power your radio transmits at (in dBm)
    txdBi is the amount of gain your antenna has
    fsl is the amount of loss in dB between the two sides of the link
    rxdbi is the amount of gain the ''recieving'' antenna has.
```
If you do have trees, buildings, bad coax cable or anything else that can impede the radio signal
(besides the open air between the antennas), try and figure out what the loss is in dB and add it to the fsl value. This'll come up with a number, probably negative. This number is the amount of radio energy that receiving side will be able to "hear" (under ideal circumstances that is!). The object of the game is to get the receiving side
hearing a signal of at least 10 dB more than what the receiving radio's http://wiki.freenetworks.org/moin/index.cgi/ReceiveSensitivity is.
You can also use the commands !range, !fsl and !rxsl in the IRC channel to do the math for you.

What is the best antenna?

There is no right answer to this, please look up the radiation patterns of antennas your are interested in and see if they will fit your needs. Parabolics are good for long distance links, Helicals, Waveguides and Yagis are generally good for medium distance links, Sector antennas are good for medium distance links or large area coverage, and Omni antennas are good for large area coverage.

How can I hack an antenna onto my wireless card?

If your card doesn't already have an antenna connector, you should return it and buy one that does (ORiNOCO, Cisco, EnGenius/Senao and a few D-Link's have proper connectors). Seriously.

I want to build my own antenna, where are instructions to do that?

The cantenna is really the only antenna that is even worth building yourself anymore as antenna prices drop slowly, and we realize what a PITA and a time sink it is to build a quality antenna yourself. But, we do understand the desire to build your own when you first get into this wireless stuff, hell, we did. The cantenna is a waveguide antenna made from a tin can, with a copper wire and an N connector, it can be built in 20 minutes and $5 worth of parts, and will give between 8 and 16 dB of gain have been reported.
Here are instructions for the cantenna: http://www.turnpoint.net/wireless/cantennahowto.html

What's the deal with reverse polarity (RP) connectors?

"Reverse polarity connectors have the normal "male" and "female" inner connector parts swapped over so that female contacts are used in the plug connector and male contacts in the jack.

Their purpose is to prevent the user from inadvertently plugging in equipment (such as a radio antenna) that differs from the type specified by the manufacturer."

Connecting to Networks

How do I find wireless networks around me?

You can use a utility to scan for networks around you. Some popular utilities are ApRadar, NetStumbler, [http://www.kismetwireless.net/ Kismet] and many more. Take a look at WarDriving and the CategorySoftware page.

Please add stuff to this question.

How do I connect to a wireless network?

This is different in each operating system, see AssociationWithNetworks and find your operating system's instructions.

How do I hack into my neighbors Wireless Network?

Knock on his door and ask if you can use his network. He'll be able to help you get on.

How do I crack WEP?

see above.

What system do I need for 902.10 Wireless on my TV

You need what we call a "DMCA Take Down Notice" operating system. Email piracy@mpaa.org with the subject line of "dvd decss movies for free" and give them your full mailing address, as well as a list of what programs and movies you want to get for free over your wireless connection.

Network Configuration help

How do I setup my network to automatically get an IP address?

This is currently covered in NetworkCommands.

What commands do I need to use?

The NetworkCommands page lists commands used to configure IP address information once you have your radio associated with the access point.

Building A HotSpot or Network

What is a captive portal?

See CaptivePortal

What captive portal/gateway software is available?

See PortalSoftware

Security Concerns

How broken is WEP, anyway?

WEP isn't secure, period, if you're interesting enough for someone to devote a lot of time to hack you. if you just want to keep people off your network, it should be fine. But it's not a alternative to using real encryption and authentication software.

So what could I use, then?

You could examine the various device level standards supported by your vendor, such as WPA/802.11i and 802.1x. Also, you might want to consider IPSEC, PPTP, or another VPN solution. These would allow you to secure your own traffic from eavesdroppers, while still allowing open access (without using a seperate AP for a secure channel).
You don't really need any device level encryption however. Using [http://www.gnupg.org/ GPG for email] and https for secure browsing and such would protect you much beter then any device level encryption ever could. It would also offer much more features (like authentication for you email) which are imposible with device level encryption. So don't be fooled in to believing that you are secure and safe with only device level encryption. You're not.

Help with windows specific stuff in NetworkCommands and AssociationWithNetworks would be greatly appreciated. I have pictures and commands for the orinoco software under windows that I can take care of, but anything else is fair game. Further wikiizing this page (like the lucent cards), and any further FAQ's would also be welcome --ForrestEnglish

[CategoryDocumentation]