I have a "black-box device" (a credit card reader, to which some klutz lost the admin unlock card...) running an unknown, but primitive, operative system. I need to find it's MAC address.

At my disposal, I have the device itself (but no access to its admin interface), a computer running Ubuntu 12.04 (where I have full sudo rights), and a regular ethernet cable. If necessary, I can probably shake up an ethernet switch, too.

How do I go about to find the MAC address of the card reader?


By the help of a friend, I now resolved this! =) This is what I did:

  1. Install Wireshark, which is available in the software repositories: sudo apt-get install wireshark

  2. Start the program with root permissions: sudo wireshark

  3. Start capturing on the eth0 device (piece of cake - click the button on the top left of the interface, select the device in the dialog and click OK).

  4. Connect the "black-box device" and turn it on. The devices will send a large amount of packages back and forth trying to establish a connection. Wireshark will capture them all.

  5. Find a packet originating from the "black-box device". Wireshark displays the originating MAC address. Voila!

| improve this answer | |

If it does connect, nmap can perform a scan.

sudo nmap -PN

Also, more obscurely, if the device has a serial port you may get it to spill its guts on boot, and this might reveal static ip details as well.

Granted, this requires a cable, and guessing or obtaining the protocol attributes.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.