Ethernet Protocol – What is a Jumbo Frame and MTU Size Impact?

ethernetprotocol-theory

I know that the frames having size greater than the MTU size should be dropped . i.e, The Ethernet frame having size more than 1522 should be dropped .

But my doubt here is what is Jumbo Frame ?

Best Answer

Jumbo means any frame with an MTU greater than the 802.3 spec of 1500. There is no set, specified number. It is a generally accepted spec to support "9000", but each manufacturer is free to call "jumbo" whatever they wish. (I've seen some as low as 5k (realtek) and others as high as 16k (broadcom))

IEEE refuses to add it because it breaks backwards compatibility.

And there's no "should" about it. A frame larger than the set max will be dropped by the NIC -- it's an error, and the OS will never know about it. (an oversized frame counter will click up, but that's all.)