What protocols operate at the data link layer of the OSI model?

At the OSI model's data link layer, protocols are used to transmit data between neighboring network nodes and manage access to the physical channel.

Main protocols of the data link layer:

• Ethernet — the most common protocol for local area networks.
• PPP (Point-to-Point Protocol) — for direct connection between two nodes.
• HDLC (High-Level Data Link Control) — a protocol for synchronous data transmission.
• Frame Relay — for transmitting frames in packet-switched networks.
• VLAN (Virtual LAN) — a technology for network segmentation at the data link layer.

These protocols provide MAC-level addressing, error detection and correction, and media access control.