Disabling Wireless Networks?

An Ominous Coward asks: "The University of Florida student chapter of ACM hosts a yearly programming competition for students throughout the state of Florida. It is based on the ACM International Collegiate Programming Contest, and for the past ten years has been very successful, currently drawing a crowd in the hundreds. However, this year was the first we had a problem with wireless networks. We doubt that cheating was the intention, as no one had SSID broadcasting turned off (as far as we know). Wireless networking gear is quite inexpensive now. And while we don't believe it affected the contest this year, we would like to take precautions for future contests. Is there any way to disable all wireless networking in an area about the size of a large lecture hall?"

yes there is a solution...

[ForestGrump]

just run a microwave oven in the back, a few cordless phones, a few rouge APs
hopefully that is enough noise to kill most networks...

or just make it very clear: NO WIRELESS NETWORKS. Walk around with netstumbler and a directional antenna. After a few people get antennas pointed at them, the networks will stop.

-Grump

only one way to be sure...

[ubiquitin]

... use a high-signal white noise generator [rfdesign.com].

AirJack

[.@.]

Simple. You simply forge the MAC of the access point (or just use the broadcast MAC), and spew dissociate/deauthenticate frames. As long as you're transmitting, nobody in range of the transmission can associate with an access point.

This was the basis for the AirJack tool.

If I recall

[Jahf]

There was a project that would broadcast tons of fake SSIDs in an attempt to obscure the right one.

Given that principle, would it be possible to create a box that intercepts and responds with junk to any 802.11 packet it encounters?

Not sure, but I've given it thought myself when giving a class where everyone is sitting there checking email (when you give a 3-day bootcamp on a subject everyone starts to drift -if- there is a distraction ... I don't care if they want to check, but they can get up and do the checking in another room ... 1 distraction leads to 2 and on and on).

You don't necessarily need to -block- 802.11 traffic if you can make the existing networks worthless by giving junk back to the 802.11 clients. Perhaps masquerading the MAC of any AP you find active would be enough?

DoS attacks for 802.11 networks

[samgrover]

There are several 802.11 denial of service attacks explained in this paper [ucsd.edu]

You will have more luck just monitoring it.

[Blaze74]

Most of the other posters here have mentioned ways to flood the network with bssids, etc. Chances are this will not work since the bssid's will be chosen by the cheaters. You will probably have more luck running kismet or some other sniffing tool to monitor the wireless network. Then you can see if anyone tries to use the wireless network.

TV kills the net

[Anonymous Coward]

Wireless AV transmitters [goldenshop.com.hk] kill WLAN. Uncompressed analog TV signals eat bandwidth like no tomorrow and these gadgets use the same ISM band as WLANs.

Re:Speaking from experience

[Halfbaked Plan]

The more interesting question is wether there was a way to detect who was doing it.