My DSL modem does both wireless and hardwired applications. I chose to do wired just for simplicity and I don't own a laptop. Is there any program or any way I can sniff out a way to see if someone might be leaching off of my wireless signal?

The only way I can think of that you would be able to is to be constantly refreshing your network status and checking for increased traffic. However if you password encrypt it, it should not be a problem. Most routers when you go to set up a wireless networking set have a password on the same general section.

Depends alot on the make/firmware/setting/etc, but alot of routers have decent logging functions under admin options, that you can turn on, or may even be on by default, that can show mac addresses that accessed network.

If some are not from a device you own, obviously somethings going on.

Try logging into your modem/router. Usually it's set to 192.168.0.1, you can figure out what your gateway is by opening up a dos window (go to the windows program menu, hit run, type in cmd) then type in ipconfig. Most routers will have a web interface. Just check for something like "attached devices" and you should be able to see if anybody is connecting thru your wireless.

If you're not using the wireless, most combo boxes have an option to disable the wireless access point altogether. Then you won't have to worry about monitoring anything.

Get a free app and stick on your computer. Use a hub, not a switch. Sniff everything. I think Ethereal is still free?

I'd be surprised if the wireless traffic made it to the computer's side of the wire. :) It most likely would just go directly out to the internet.

The person my room mates and I are stealing internet from hasent been able to spot us yet. I am pretty sure of that. Once he tried to make his network secured but I think he got frustrated and gave up.

If I could just figure some way to spontaneously reboot his computer every now and again when he has the internet all whacked out, I would be a happy camper!

Actually we are hard wired again, but we just havent been able to get our freaking D-link to work right so 2 of us are still leaching off Linksys dude till we can figure out how to get our own crap working right.

Best way to keep people off your router is to filter by MAC address. Your packets are still unencrypted but nobody can log on to your network without first having their MAC address entered into the router.

Spoofing MACs is pretty easy for the determined. It's about as useless as not broadcasting your SSID.

Understand that if you use any sort of wireless network that you don't control, your information can be seen completely by the owner of the access point with a few simple tools. Furthermore, if you are "stealing" wireless, you'll most likely be accessing it unencrypted, which means all your information is transmitted out in the clear.

Spoofing MACs is pretty easy for the determined. It's about as useless as not broadcasting your SSID.

Correct me if I'm wrong, but you'd actually have to know what mac address to spoof wouldn't you?
(or can you read that from the signal itself? I.e. does it send the mac address unencrypted?)

I personally just named my access point my address + "Ask for access"...two of neighbors pay me $5 a month for acces.

Correct me if I'm wrong, but you'd actually have to know what mac address to spoof wouldn't you?
Yeah, cause there's no way I can see REAL MACs that access your network, now could I :)

Spoofing MACs is pretty easy for the determined. It's about as useless as not broadcasting your SSID.

"The determined" would be breaking into thier house and getting the MAC off of thier computer? You can't stumble onto a network with MAC filtering. It doesn't allow you on at all. Only thing you could do is get on one of the allowed clients, find the MAC, and clone it. Now if there a way around this, please, enlighten me.

You can sniff MAC addresses without being connected to an access point.

When is MAC info exchanged? During DHCP renewal?

Every packet.

Well thanks for the correction, thats good to know.

Yup, every packet has both the source and destination ip address, and the source and destination IP.

The point of the router is to take that packet and figure out where the next hop goes to....at which point it substitutes it's own new mac in the source and the next hop's mac in the destination.

I.E. if you can sniff the signal, you'll know every mac address there.

Yup, every packet has both the source and destination ip address, and the source and destination IP.

The point of the router is to take that packet and figure out where the next hop goes to....at which point it substitutes it's own new mac in the source and the next hop's mac in the destination.

I.E. if you can sniff the signal, you'll know every mac address there.


Ahhhh, good to know. That was actually my next question.