Ethernet Type Codes
The Ethernet Type field (EtherType) identifies the protocol encapsulated in the payload of an Ethernet frame. The detailed reference lists are maintained across the following pages:
Ethernet Type Codes
Protocol type field values
Vendor Codes
OUI / MAC address prefixes
Multicast Addresses
Well-known multicast MACs
There are also less complete lists maintained by IANA and the IEEE. IANA's is less complete because it is not aggressively maintained; IEEE's because some entities apparently ask that their allocations not be publicised.