@mjk For those unfamiliar, there are myriad networking protocols that operate over Ethernet that are not IP.
That includes DECnet of course, and MOP traffic including periodic MOP SYSIDs, and DEC thoughtfully reserved Ethernet type 0x6006 for their customers, so who knows what that type contains.
Random Ethernet type thought: does VSI or HPE “own” 0x6006 now?