I have two gigabit-thunderbolt adapters for my new MacBook. Each appears to have its own mac address, and each has to be registered individually on my company network. I am surprised, and concerned that having the mac address on the adapter represents a security risk, should I lose one. Is this a real problem?
MacBook Pro with Retina display, OS X Mavericks (10.9.2)
We have a MacBook Pro Retina also with two Thunderbolt ports, with which we use that same Apple ethernet adapter.
Although I haven't tried two of these, I seriously doubt, that for $29, these adapter have any active circuitry that would imbue them with unique MAC addresses. But I have used an ethernet adapter and a firewire adapter, and interchanging them doesn't affect their behavior. The computer sees one device type of each.
Based on my tests, it is more likely that the computer evaluates the behavior of each device connected to a Thunderbolt port and identifies which type it is. Even though I haven't personally tried two ethernet adapters, I hypothesize that If the computer sees two ethernet adapters, it assigns a unique MAC address to each, and that's why you have each MAC address has to be registered with the router at your company.
If you want to do an experiment to confirm or refute this, please try each adapter individually in a Thunderbolt port and see what MAC address appears in Network Utility Info tab window when you select En(x). Then move the same adapter to the other Thunderbolt port and see if it displays the same MAC address. That's what my MacBook Pro does when I move it from one
Then try the same single-adapter test using the other adapter. If I am correct, when connecting a single adapter, you should get the same MAC address you saw with the other adapter on either port. If my hypothesis is correct, then you don't have any security risk if losing your adapters.
I would appreciate your reporting your detailed results in this same thread.
Thanks,
Bob
Message was edited by: RHBernard
mac addresses for thunderbolt-gigabit adapter
