IEEE 802.3 vs EthernetII

IPv4/6 uses Ethernet II frame format almost exclusively. In 802.3 there must be a LLC/SNAP header to indicate which upper layer protocol to use. The first 20 bytes of both framing format are the same. The differences is

• 802.3 : uses a 2 bytes length field
• EthernetII: uses a 2 bytes type field. 

To differentiate between them 802.3 values < 0x0600 (1536), Ethernet II >= 0x0600

802.2 LLC header:

DSAP address	SSAP address	Control field	Information field
8 bits	8 bits	8 or 16 bits	N * 8 bits

802.2 SNAP haeder:

LLC			SNAP
AA	AA	03	00	00	00	08	00
			3 octet OUI			2 octet TYPE-field