When I first started working, I was very interested in learning about the Linux kernel. Specifically the TCP/IP stack and the inner workings of an Ethernet controller. To learn more, I picked one of the most widely used Ethernet controllers at that time, the Intel 82559 10/100 Fast Ethernet Controller and one of its open-source drivers, the eepro100.

Thought 82559 chip is no longer manufactured and the eepro driver has been deprecated, this article will still serve as a guide for how an ethernet controller works. We’ll look at how the eepro100 driver interfaces with the Intel 82559 chipset and how the 82559 converts the packets sent by the driver to signals transmitted over physical ethernet cable.

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