Which OSI layer does a Network Interface Card (NIC) work on?

The Network Interface Card (NIC) operates primarily on the Physical layer of the OSI model. This layer is responsible for the actual transmission and reception of data over a network medium. The NIC provides the physical connection between the computer and the network, converting digital data into electrical, radio, or optical signals for outbound data, and vice versa for inbound data12.

Additionally, the NIC also has functionalities that extend to the Data Link layer, which is responsible for node-to-node data transfer and handling the physical addressing of packets through MAC addresses3.

References:

Information based on the Certified Network Defender (CND) course material and study guide.

Additional details from EC-Council’s official Certified Network Defender (CND) resources and other authoritative sources on network interface cards and the OSI model132.