C job interview - casting and comparing

Question

I was confronted with a tricky (IMO) question. I needed to compare two MAC addresses, in the most efficient manner.

The only thought that crossed my mind in that moment

Answer 1

If your interviewer demands that you produce undefined behavior, I would probably look for a job elsewhere.

The correct initial approach would be to store the MAC address in something like a uint64_t, at least in-memory. Then comparisons would be trivial, and implementable efficiently.