Blocking an unauthorised wireless extender

Our small store has for years put up an open unencrypted wireless router with the SSID storename-public, as a community service, with the 'public' in the SSID so that users would know not to transmit sensitive info across it.

Recently we noticed a dramatic slowdown and realized someone nearby has put up an extender with the SSID storename-public_EXT.

We have several problems with this:

The first being of course the impact on our own throughput.
Another problem is the possibility that they are actually capturing private info and we will get the bad rep.
The third problem is the simple fact that they are using our network in an unauthorised manner.

We'd like to keep the open wireless up. Is there a way to block the extender without requiring passwords on our own router? What would be the effect of changing our SSID to something 32 chars long; would that stymie their extender? The extender apparently clones our own MAC address so I can't block that.

Richard

Posted 2011-07-23T13:29:11.987

Reputation: 31

Where do you live? What model is your router? – KCotreau – 2011-07-23T13:30:49.853

2Regarding private info - blocking extenders really won't help with that. WiFi is just radio waves, after all, and anyone with a laptop can capture traffic. – user1686 – 2011-07-23T13:45:52.340

1Major issue is not really the possible capturing of private info - if someone is dumb enough to transmit over a network that says it is public it's their own risk. The essence of the private info issue is (1) the extender spreads the availability of the private info beyond our own building and (2) it has our name associated with it. For that matter I don't even know if it's possible for them to independently capture data sent via the extender. The main problem for us is not the private info issue it's the bandwidth burden. – Richard – 2011-07-23T14:43:02.810

1As @KCotreau said, it would help to know more about your hardware. This essentially determines which options you have from your router's side. – slhck – 2011-07-23T15:27:20.730

As @grawity said, I was not even sure you could limit this, but I still wanted to know more before I was committal. – KCotreau – 2011-07-23T15:36:49.730

If your router can run DD-WRT you might look at installing ChilliSpot is supposed to have options to limit bandwidth for users. (See http://www.dd-wrt.com/wiki/index.php/Chillispot for more detail)

– sgmoore – 2011-07-23T15:52:54.540

Answers

Can't see how you can do much about this unless you implement some form of user or device access control - check the options in your router's setup. If you are offering a free wifi service, some access management companies, for example Worldspot, will give you a free account to setup a ticketed access system, although you will have to check whether your internet access device is compatible - it certainly works with anything running DD-WRT

As an aside there are legal implications in many countries in offering a public wifi hotspot so do make sure you know your obligations and liabilities.

Linker3000

Posted 2011-07-23T13:29:11.987

Reputation: 25 670

We live in Vermont. Router is a Rosewill 54M - a $39 Newegg special that replaced a multi hundred dollar Netgear that lasted exactly 6 months, a couple of years ago and has soldiered on gamely ever since. It has very few utilities built in. We're aware that public networks are risky and are willing to assume that, but don't want some third party extending that risk without our input. – Richard – 2011-07-23T19:58:16.810

I'm willing to buy a more elaborate router that might have settings that could accomplish this (block the extender) if someone has knowledge of such. – Richard – 2011-07-24T04:06:49.290

It looks as though the router you are using is limited in features based on what I'm reading here and really you won't be able to do anything further with it.

I would type up a polite note and stick it on each of your neighbor's doors early one morning before the start of a business day and tell them that you are aware that someone is doing this and you would like it to stop.

LawrenceC

Posted 2011-07-23T13:29:11.987

Reputation: 63 487

Its hard to block something that you are giving away for free. You can use a laptop/wifi locator to track down the source of the extender and ask them to stop. If they refuse, you can go to the police, as what they are doing is considered theft. People have been arrested and convicted of unauthorized wifi usage.

Keltari

Posted 2011-07-23T13:29:11.987

Reputation: 57 019