[j16sdiz]

Except there is a trick: In a switch, a port can only associate with limited number of hardware addresses. If you spam it with generated hw address, some switches put that port into open mode, some switch shutdown that port, the other just misbehaves. Almost none of them keep a LRU list correctly

[pclmulqdq]

I think you're missing the point. Electrically, you can't "spam" anything on a tapped cable. It will just go down at the physical layer when you try to transmit unless you cut it and insert yourself between its endpoints (as a switch, essentially).