Protocol

A protocol is identified by its 16-bit protocol identifier carried in the Ethernet II/SNAP type field (often referred to as the Ethertype). The protocol type is written as a hexadecimal number from 0001 to ffff. Even if the table is empty, some protocols are implicitly assumed to be listed in this table as type SNAP (such as IPX and AppleTalk). This can be overridden by explicitly setting their protocol to Ethernet II.