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humdinger · 01-19-2005

I plan on using Netstumbler to detect rogue access points within my organisation's premises.

From what I've read, I shouldn't have a problem in detecting the presence of a wireless access point, however I could face some difficulty in determining the exact location of the device.

It would appear that two main solutions are offered. The first would be to use a laptop with a highly focused antenna (Yagi or Parabolic would seem ideal), and use this setup from the likes of the car park. From there I could "paint the walls" with the antenna and should be able to determin which office the access point is located in, before heading inside for a closer examination.

My other option appears to be to use a PDA and wander up and down the halls, scanning for access points. From what I've read it seems that this is the best method for detecting the presence of an access point, but is not ideal for determining the exact location of an access point (or even if it's a foreign device).

It may help if you have some background information on the organsiation. It's a fairly small company, yet the building is moderately sized - 3 stories high, with two wings containing open plan offices. The budget is limited, which is why we can't simply install a lot of sensors around the building to perminantly scan the area, nor can we afford the services of an external "wireless scanning expert/contractor". We currently have no wireless networks within the organisation (that we know of!).

Now to the point of the post (the questions).

Firstly, can anyone spot any major flaws in the above two options, or point out a solution that I may have missed.

Secondly - would it be possible to use a Yagi or Parabolic antenna indoors and sweep the building from my desk? Or would I have to wander around juggling a laptop and large antenna?

Thirdly - It would appear that both the Yagi and Parabolic antennas offer very focused beams, is one more ideal than the other for this type of use?

Forthly - Is it possible to attach an external antenna to a PDA with a compact flash or SD I/O card based wireless adaptor? If so, which adaptor would you recommend?

Finally - Could I use the PDA in such a manner, whereby once I detect a wireless access point I could then dampen the field (by wrapping it in a foil bag). I could then use this limited range to help me get a better idea of where exactly the access point is located (using the logic - if it detects it whilst the signal is dampened then it must be close).

Thanks for taking the time to read this post. I'd appricate your advice before I spend any money on this project.

01-19-2005	#1 (permalink)
humdinger Registered Member Join Date: Jan 2005 Posts: 8	Detecting Rogue Access Points I plan on using Netstumbler to detect rogue access points within my organisation's premises. From what I've read, I shouldn't have a problem in detecting the presence of a wireless access point, however I could face some difficulty in determining the exact location of the device. It would appear that two main solutions are offered. The first would be to use a laptop with a highly focused antenna (Yagi or Parabolic would seem ideal), and use this setup from the likes of the car park. From there I could "paint the walls" with the antenna and should be able to determin which office the access point is located in, before heading inside for a closer examination. My other option appears to be to use a PDA and wander up and down the halls, scanning for access points. From what I've read it seems that this is the best method for detecting the presence of an access point, but is not ideal for determining the exact location of an access point (or even if it's a foreign device). It may help if you have some background information on the organsiation. It's a fairly small company, yet the building is moderately sized - 3 stories high, with two wings containing open plan offices. The budget is limited, which is why we can't simply install a lot of sensors around the building to perminantly scan the area, nor can we afford the services of an external "wireless scanning expert/contractor". We currently have no wireless networks within the organisation (that we know of!). Now to the point of the post (the questions). Firstly, can anyone spot any major flaws in the above two options, or point out a solution that I may have missed. Secondly - would it be possible to use a Yagi or Parabolic antenna indoors and sweep the building from my desk? Or would I have to wander around juggling a laptop and large antenna? Thirdly - It would appear that both the Yagi and Parabolic antennas offer very focused beams, is one more ideal than the other for this type of use? Forthly - Is it possible to attach an external antenna to a PDA with a compact flash or SD I/O card based wireless adaptor? If so, which adaptor would you recommend? Finally - Could I use the PDA in such a manner, whereby once I detect a wireless access point I could then dampen the field (by wrapping it in a foil bag). I could then use this limited range to help me get a better idea of where exactly the access point is located (using the logic - if it detects it whilst the signal is dampened then it must be close). Thanks for taking the time to read this post. I'd appricate your advice before I spend any money on this project.