Maximum Frame Size

TryPingingTheServer

Just a stupid question...

I keep reading that the maximum frame size (header + payload) is 1518 bytes.

1500 bytes of data with 18 bytes of header.

Destination - 6 bytes
Source - 6 bytes
Type - 2 bytes
FCS - 4 bytes

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18 bytes

But what about the 7-byte preamble and 1-byte SFD field? Why are they not included in the header size? Shouldn't the header size therefore be 7+1+6+6+2+4 = 26 bytes?

tiersten

Not counted. They're removed by the ethernet chip before anything else even sees it.