Which layer do hubs operate at in the OSI model?

Hubs operate at Layer 1 of the OSI model, which is the Physical layer. This layer is responsible for the transmission and reception of raw bit streams over a physical medium. Hubs are basic networking devices that connect multiple Ethernet devices, making them act as a single network segment. They facilitate communication by repeating incoming signals to all ports, without regard to addressing or determining the source or destination of the data.

Since hubs deal exclusively with the physical aspects of network connections, including the electrical and mechanical properties of the medium, they do not operate at the Data Link layer (Layer 2), Network layer (Layer 3), or Transport layer (Layer 4). Each of these upper layers adds different functionalities such as error detection, routing, and end-to-end communication, which hubs do not perform. Thus, the correct identification of hubs operating at Layer 1 underlines their fundamental role in networking as devices that manage the physical connections between multiple devices.