Friday, June 17, 2011

Map Wi-Fi Router MAC Address To Physical Location

If you haven't seen this research android map by Samy Kamkar, just read on.

From the page:
"android map exposes the data that Google has been collecting from virtually all Android devices and street view cars, using them essentially as global wardriving machines. You can use this tool to accurately locate virtually any router in the world, as well as position iPhones and Android phones.

When the phone detects any wireless network, encrypted or otherwise, it sends the BSSID (MAC address) of the router along with signal strength, and most importantly, GPS coordinates up to the mothership

This page allows you to ping that database and find exactly where any wi-fi router in the world is located. Note that iPhones also send this BSSID and Cell Tower Information up to Apple, as well."

The search result looks like this:

Note that, Technitium MAC Address Changer (TMAC) cannot change MAC Address of your router. You can change it from web interface the device provides. MAC address changing feature might not be available in all routers though.

Tuesday, June 7, 2011

Why You Need To Change MAC Address?

I have been asked many times this question, in person as well as over email. Many people are clueless that you can even change MAC address and give open challenges, so forget that they would know why there is a need to change a MAC address.

Some people think that websites on Internet can track users using MAC address and so they must change it! Well, your MAC address wont go further than the first router the IP packet gets to. Its because, MAC address is used as unique identifier at data link layer (OSI layer 2), like for example your local Ethernet, while the IP packet being forwarded over Internet is at network level (OSI layer 3) and uses IP Address as a global unique identifier (which websites can see and track). And when an Ethernet frame reaches a router, the router's MAC address is used to send the frame forward. So, clearly this is not a reason to change MAC address!

There are many reasons you would want change MAC address, some legitimate others not so. I am listing some of the legitimate reasons while you wonder what the other reasons might be!
  • Your ISP uses MAC address to identify or authenticate your Internet connection. So in case your network card goes boom, the new card you replace it with will have different MAC address and so the Internet wont work. So changing the MAC address to old network adapter is the quickest fix instead of telling your ISP to register your new MAC address which may take lot of time.

  • If you want to access a network, which limits access based on MAC address, from another machine then you can change MAC address to the one for which you have access. Note that only one computer would be able to access the same network (no two computers can have same MAC address on same network to access it without any problem)

  • A very important reason is privacy. Your MAC address can be seen by everyone on the local Ethernet network using many simple tools. A hacker on local network thus can track machines (and thus you) on the network. This is especially a threat when you are on a wireless network and are using a public WiFi network like in coffee shops, hotels or airports.

  • If your original MAC address is revealed, an hacker can use it to impersonate you! On many networks (wired or wireless) access is restricted based on MAC address to avoid access to unauthorized devices on the network. So, when you go offline, someone can use your machine's MAC address and access the network as 'you'.

  • You can get a new IP address lease from DHCP server by changing MAC address. On many networks, DHCP lease is set to last many days or is associated directly with a MAC address such that you get the same IP address all the time.

The reasons I listed above are just the ones that came to my mind while writing this post. There are many more reasons (sometime bizarre) to change MAC address.

If you change MAC address for some reason not on the list above, do post it as a comment below.

    Thursday, June 2, 2011

    ComputerWorld: 10 Must Have Utilities For Small Networks

    Technitium MAC Address Changer (TMAC) is on the top '10 Must Have Utilities For Small Networks' list on Its been a while it was listed in there, if you didnt see, just check it out.

    You can also check out the editorial review of TMAC by