The Ethernet as we see it today is a result of many stages of evolution. As a result, the Ethernet frame format at the link layer also has seen many changes. One might expect a consistent format of link layer frames as we usually study in text books, in actual practice this is not the case. Please refer to the manuscript for complete abstract.
Cite
@article{arxiv.1610.00635,
title = {A Comparison of Existing Ethernet Frame Specifications},
author = {Muhammad Farooq-i-Azam},
journal= {arXiv preprint arXiv:1610.00635},
year = {2016}
}