Can a radio share a MAC address with the ethernet interface of an access point?

Question

I have a situation where I have found the BSSID to have a MAC address congruent to the MAC address of the ethernet interface.

1. Is this possible?
2. Does this happen with all access points?

Answer 1

That shouldn't happen. Each interface should have a unique MAC address.

Actually, each interface's MAC address should be globally unique but that isn't really the case any more. However, the vendor needs to take care that an address collision is extremely unlikely (re-use addresses only between different geographic regions).

Using the same MAC address in different networks (perspective of wired nodes vs perspective of wireless nodes) should work though. I don't see a direct problem in your case. MAC addresses need to be unique for different L3 interfaces. A WAP in bridge mode works on L2 and only really requires a MAC address for its SSID and for its management interface.