Ethernet: MAC

What this Ethernet MAC layer interview question tests

This is an easy digital-design question that checks whether a candidate understands the role and scope of the Media Access Control (MAC) layer in high-speed Ethernet systems. It is typical of FPGA and hardware-design interviews where familiarity with the OSI stack and standards compliance matters.

The MAC layer sits between the physical layer (PHY) and the network layer, and is responsible for a well-defined set of frame-level operations. Candidates should be able to distinguish between what the MAC layer handles — such as frame formatting, address filtering, and synchronization — and what belongs to the PHY (signal integrity, bit recovery) or higher layers (routing, IP logic). This question rewards knowledge of the Ethernet standard and practical FPGA design patterns.

• Frame composition and stripping
• Address recognition and filtering
• Flow control and backpressure
• CRC insertion and validation
• Inter-frame gaps and preamble handling