Which type of Ethernet frame size is most commonly used?

The most commonly used type of Ethernet frame is Ethernet II. This Ethernet frame format is widely recognized and utilized because it includes an EtherType field, which allows it to identify the protocol encapsulated within the frame, such as IP or ARP. This feature makes it particularly versatile and suitable for modern networking protocols that operate over Ethernet. As a result, Ethernet II has become the standard frame format in most network environments, especially in scenarios where TCP/IP stacks are deployed.

In contrast, while 802.3 is a specification that also defines Ethernet frames, it lacks the EtherType field found in Ethernet II, using a different method for encapsulation. Jumbo frames refer to frames that exceed the standard maximum transmission unit (MTU) size of 1500 bytes; they are used in specific scenarios to improve network efficiency but are not the standard frame size used in typical Ethernet networks. The term "Ethernet frame size" is rather general and does not specify a type, making it less applicable when identifying the most commonly used format. Therefore, the choice of Ethernet II represents the most widely adopted standard for Ethernet communications in contemporary networks.