How can I tell if somebody is using our wifi?

[MadMommaMemoo]

I have strong suspicions that our neighbours are using our wifi.

Dd is friends with their dd and says she might have mentioned our password to them.

Our wifi is suddenly really slow, and despite neighbour telling me a few weeks ago they couldn't afford Internet connection their dd has been on msn to my daughter and facebook. We live in a semi so I'm sure they'll pick up our signal.

change your password

3 short but very wise words

If they where smart they would monitor the network and only use it during the hours you don't so you wouldn't notice they would also change the ID/MAC of the PC to mimic one of yours and change the router settings so you can't kick them out, but it sounds like they have no brains so do as told that should do it.

You should have a way to see your router settings through a web browser or desktop application. This will have a place to view what is on your network.

And, as said, change your password!

I have no idea how to change my password!!!

change your router setting.

This is theft, possibly worse than theft as if they're illegally sharing files or even worse downloading very dodgy porn then you'll be held responsible. And in this age of "fair use limits" they could also lead to your broadband being cut off or "throttled" to a slow speed if they cause you to use too much. The Police have arrested people for doing this.

As people have said definitely change the passwords and make sure that you enter it into your daughters machine(s) so she doesn't actually know it.

I'd also look into your wireless networks security settings and consider locking your network down to the MAC addresses of each machine that you want to allow access onto your wireless network. The MAC address is a "unique" ID that every machine has so, in theory, you lock your network down to exactly the people who you want to be on it. Yes it is possible to hack the MAC address of a computer but it's fairly technical and would also involve more technical jiggery pokery for them to find out an address that would work. So it's out of the reach of most people.

As a final thing I'd also mention to your daughter that someone is accessing your network without permission, that that's illegal, that you've gathered the unique ID of the machines that have been doing it and are going to speak to the police (even if you're not).

Some people.....

MAC address was never designed for the purpose of security which is it now, it was made to identify the origin of files sent down a daisy chain of scsi devices on a network.

If you are using windows you can download programs (I will not say what the general term for them is) that look for over air data packets and then allow you to mimmic the id contained in them, it's not rocket science any idiot can do it, if you are using Linux you don't need a program you can change all the PC ID information manually to what ever you like (if you know how for that one you do need to know what you are doing).

Never rely on MAC addresses for anything they mean nothing, a wireless connection is only as secure as the people within range are stupid.

The only truly secure internet is wired.

"Never rely on MAC addresses for anything they mean nothing, a wireless connection is only as secure as the people within range are stupid."

Using them does stop the "casual" "borrower" who has got the password to the network from somewhere/someone. It elevates the required activity from an easy entry of a password to something a bit more determined, and once someone reaches that level of determination it's a lot harder to stop them getting in no matter what you do.

So I wouldn't rely on them alone but in this case even if the DD does get and share the password it's probably going to deter most people from doing what's required to hack into the network.

Look on your router to find make and model. Then google to find user manual. Follow instructions to change password.
Once changed you will need to set up access for all devices again. It would be a good idea to do this for your daughter so she doesn't know it and can't accidentally share it.

Someone was 'piggy-backing' on mine a few years ago. I kept getting letters from BT saying I had exceeded my useage amount every month and had to pay a few ££ extra. But I could never prove someone else was doing it, I thought I was on MN too much.

When I got a new laptop and set it up properly they stopped being able to pinch it.

Also you might want to change the SSID ( the name that is broadcast) and then set it to not broadcast once everything is set up, so they won't see it next door.