Quiz Entry - updated: 2026.07.14
What does OSI Layer 2 (Data Link) do?
OSI Layer 2 (Data Link) handles framing, physical (MAC) addressing, media access, and error detection (FCS) for local delivery on the same network. Switches operate here.
Layer 2 = Data Link Layer
Handles physical addressing and local delivery on the same network.
Key functions:
| Function | Description |
|---|---|
| Framing | Creates frames from packets |
| MAC addressing | Physical addresses |
| Error detection | FCS/CRC checks |
| Media access | Controls when to transmit |
Devices: Switches operate at Layer 2
Memory tip: Layer 2 is the "Data highway" - manages traffic on the local road (LAN).
Go deeper:
Data link layer — framing, MAC addressing, media access, and error detection.- MAC address — the Layer-2 physical address used for local delivery.