Explain the difference between a hub and a switch in networking.

Hubs and switches are both networking devices used to connect multiple devices in a local area network (LAN), but they operate in different ways. Let's explore the technical details of each:

  1. Hub:
    • Functionality:
      • Hubs operate at the Physical Layer (Layer 1) of the OSI model.
      • They are basic networking devices that work by broadcasting data to all devices connected to them.
    • Collision Domain:
      • All devices in a hub share the same collision domain. When one device sends data, all other devices connected to the hub receive it.
      • This can lead to collisions, where two devices try to transmit data simultaneously, causing data corruption and retransmissions.
    • Bandwidth Sharing:
      • Since all devices share the same bandwidth, the overall bandwidth is divided among all connected devices.
    • Address Learning:
      • Hubs do not have the capability to learn MAC addresses. They simply forward incoming data to all connected devices.
    • Example:
      • The classic example is a simple Ethernet hub.
  2. Switch:
    • Functionality:
      • Switches operate at the Data Link Layer (Layer 2) of the OSI model.
      • They are more intelligent than hubs and make forwarding decisions based on MAC addresses.
    • Collision Domain:
      • Each port on a switch is its own collision domain. This significantly reduces the chances of collisions, as each device has a dedicated communication path to the switch.
    • Bandwidth Allocation:
      • Switches dynamically allocate bandwidth to each port, allowing for full-duplex communication and eliminating the bandwidth-sharing issues seen in hubs.
    • Address Learning:
      • Switches have a MAC address table, allowing them to learn the MAC addresses of connected devices. They use this information to make forwarding decisions and send data only to the intended recipient.
    • Example:
      • Ethernet switches are common in modern networks, providing more efficient and reliable data transmission compared to hubs.