So, for the past while, I've been noticing a severe bandwidth problem with my computer, where my connection (a private line) has about half the download speed it should at best. So my question is, is there any way I can find out if someone is stealing my internet?

If your using a wireless router you most likely can, otherwise I think the best you can do is follow the line back to the box and make sure nothing is amiss.

Post has been edited 2 time(s), last time on Dec 31 2008, 3:52 pm by Elvang. Reason: Nvm

Yes, it is wireless, but I have no idea how to detect them.

Log into your router and check the DHCP Clients list, it should list the address of every device connected to the router; alternatively you could start pinging addresses starting with 192.168.1.100(you if your comp is the only device).

The above code assumes your router assigns addresses starting at 192.168.1.100, you'll have to change the address(192.168.1.%z) and/or the start/end values(100/255) for %z if it assigns addresses differently. After its done pinging just type replies.txt and find all instances of Reply, each one indicates a device connected to the router.

In your router settings, change your wireless security type to WPA and set a new password.
It is much more likely that your ISP is acting up though.

If you have any hackerish neighbors nearby, use WPA encryption, as it's harder to break into, if not, you can just go with WEP

Or for ultimate security, only allow authorized MAC addresses in addition to WEP.

MAC address spoofing is easy.

You could always knock the DHCP client limit down to 1, when you can't connect then someones using your net. Also depending on your router, you might be able to do fun things like create hundreds of fake access points. If I find the link to the tutorial I'll post it...

How easy is it to locate a valid MAC address given an arbitrary person's network with whom you've no relation? Though I suppose you could always brute it...
I have MAC address filtering, WEP, and turned off broadcasting. ;o

You sniff the connection once you've cracked their WEP key (trivial, see aircrack). MAC addresses are sent with every packet.

You have to brute force in order to get the WEP cracked.. So then what would be the point of spoofing the MAC if you've already cracked the WEP?? I really doubt people most people who setup a home-network, know about MAC address recognition

He wants to tell if his is being used right?

Turn on your router log. Mine has it under Adminstration -> Log. After a while, go into it and see if your IP address is the only one on there. That will tell you.

Don't secure your routers... we need to blanket wi-fi networks over our cities because we are so far behind on technology and our government would rather be destructive than creative.


So what's the news deathman? Was someone stealing your bandwidth?