My computer MAC Address has been registered in a specific wired LAN network. But yesterday, I had my laptop repaired and the motherboard was replaced. Therefore, it has a new MAC Address and it cannot connect to the network anymore.

How can I find the old MAC Address, so that I can possibly spoof it to get back on the network? Unfortunately for various reasons it is not possible to add the new MAC to the registry.

I am using Yosemite version 10.10.3.


Luckily, the operating system keeps a record of almost everything, including the connections made. After playing around a bit (and help of some others), I could find the old MAC address in the following file:


Since I am looking for the wired network, I need to search for en0 and it gives me something like this:

en0   1500  <Link#4>    01:02:03:04:05:06        0     0        2     0     0

which contains my MAC address.

  • What is the point of answering your own question, 4 minutes after having asked it? – MariusMatutiae Jul 8 '15 at 10:18
  • 1
    So that someone with the same problem in the future can benefit from the answer. – Mahdi Jul 8 '15 at 10:35
  • Yes, that's a good point. For difficult questions, though. – MariusMatutiae Jul 8 '15 at 10:37

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.