MAC Address Changed?

user1013264 asked:

I was wondering if the following MAC address is a valid one?

00:13:74:00:00:00

We have an automated network registration on the system whereby users can plug in their computers and register on the network with a given username/password. Anytime they want to register, the system would detect their MAC and make sure that no one else is using the same MAC under a different username. We have a user who is unable to register because her MAC address “conflicts” with someone else. I was wondering if that MAC is valid in the first place since the first 3 octets recognize vendor and last 3 should be different. I am not sure if all 0s would be fine because that looks too generic. Is is possible that the MAC address could’ve changed? If so, what are the possible causes of it? Any tips/suggestion and assistance would be appreciated. Thank you.

My answer:


The Wireshark OUI Lookup tool says…

00:13:74 Atheros Communications, Inc.

So, yes, it’s probably a real wireless NIC.

As mulaz noted, there have been instances where vendors have released more than one card with the same MAC address. This causes all sorts of trouble if both cards end up on the same network.


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