Hi Bit,
That MTU of 1500 actually refers to the actual data portion (that is passed
down from the IP to DataLink layer) of the frame and not including the
thernet header. When you add the ethernet header, the frame can reach up to
1522 Bytes, as this link actually says.
http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080094665.shtml#frame2
If you have access to Safari, check this book - its an excellent resource
when it comes to these basics:
TCP/IP Illustrated Vol ! - By W. Rachard Stevens, Chapter 2.
HTH
Sadiq