Calculate minimum and maximum Ethernet (IEEE 802.3) frame size from frame format
The preamble and SFD do not count towards the frame size since they are only part of the Ethernet packet (i.e., layer 1), not of the Ethernet frame (i.e., layer 2); see here, for instance. Recall that Ethernet is not a pure layer 2 protocol but actually a mix of layers 1 and 2.