Hotel guest caused interference with his AP. Why?

[BobY777]

This is crazy.

I went in to my clients hotel tonight to check out the WiFi system.

I noticed that the switch data light for a particular AP for the hotel channel 11 AP was acting crazy. It was sending data like crazy the whole time I was there. At least 1 hour.

Upon checking further, I noticed an interferring signal (with a different SSID) that was on the same channel as the hotel's channel 11 AP.

I immediately went home to get my directional antenna with a high front to back ratio for direction finding.

That antenna enabled me to walk right to the hotel room that the interferring AP was in.

It was very interesting. That interferring AP was on for a very long time. But when I walked past the room window a couple times (the curtin was pulled) homing in on the location, all of a sudden the signal was turned off.

I found the room.

Now why would someone turn on an AP like that in a hotel?

It had a different SSID, so no one in the hotel would associate to it. Seems that he just wanted to interfere with our channel 11 signal, which was nearby.

I have had some problems in the past with some of our APs locking up, where they needed repowered. However some of it, I think, was due to a bad switch. This interference had the data light on the switch going crazy. I wonder if this was enough to lock up the APs?

I wonder what kicks this guy gets out of doing this.

[spiderbite]

Hmm, lets noodle this out.

You may have had many associations on the crazy AP

Did you browse into the AP to see who was associated?

The guy with the AP may have just been ignorant.

Some people think (I am not making this up) that if you buy an AP or steal one off the wall that by simply turning it on you will have wireless internet access!

He would have had to been transmitting copious amounts of data to actually interfere with channel 11.

Now he was sending broadcasts and ICMP requests across 11 which take up very little space, but could be annoying.

Now if he could plug into an ethernet jack in the wall and somehow get network connectivity (very bad) that might do it.

Next time check the association table of the AP and see who is associated (might be too many)

Without a wireless analyzer like airmagnet etc or a network analyser like airopeek etc it would be hard to call this interference
just yet...

Did the switch stop when he stopped?

[twstdchild]

I seen APs set up in guestrooms before when the hotel offered wired Internet. With one MAC ID logged for the router, you can usually get a bunch of nearby rooms wireless connectivity.

This is really a problem when a hotel has both a wired and wireless service offering.

You see people in meeting rooms bring in wireless APs all the time and interfere with guestroom Wi-Fi. :-(

[BobY777]

Hi spiderbite and twstedchild:

There is no wired ethernet that the AP can be plugged into. It was a Senao AP, so this guy must know something about good APs.

I was going to see if I could associate to it and see what he was displaying, but by the time I found out what room he was in, he turned it off. He probably saw me walking near his room with my directional antenna. I should have tried to associate first.

I didnt' think to go back to the equipment room to see if the crazy flickering stopped when his AP went off. But don't some data lights fliker a lot on switches even when they are operating properly? I'm not sure.

Thanks to both of you.