Switch

cd alt text

A Switch is a networking device used to connect multiple devices within a Local Area Network (LAN). It operates at the Data Link Layer (Layer 2) of the OSI model, but some switches also function at the Network Layer (Layer 3) (known as Layer 3 switches). A switch is more efficient than a hub or bridge due to its intelligent traffic management.

Functions & Characteristics

  1. Device Connectivity – Connects multiple computers and network devices in a LAN.

  2. MAC Address Table – Stores a list of MAC addresses along with their corresponding ports in its RAM.

    • MAC addresses are learned during the first broadcast from any port.
    • Subsequent communication is sent directly to the intended device without broadcasting.
  3. High-Speed Communication – Provides faster data transfer rates compared to hubs and bridges; often referred to as an intelligent hub.
  4. Full-Duplex Operation – Allows multiple devices to send and receive data simultaneously without collisions.
  5. Speed Support – Commonly supports 10/100/1000 Mbps (Fast Ethernet and Gigabit Ethernet).
  6. Collision Domain Reduction – Each port on a switch represents its own collision domain, greatly improving network performance.