Ethernet switching is a networking technology that involves the use of Ethernet switches to forward data packets between devices on a local area network (LAN). Ethernet switches are devices that operate at the data link layer (Layer 2) of the OSI model and are commonly used to create efficient and dedicated communication paths between devices within a network.
Here’s how Ethernet switching works:
- Data Forwarding: When a data packet arrives at an Ethernet switch, the switch examines the packet’s destination MAC address. It uses this information to determine the appropriate output port through which the packet should be forwarded.
- MAC Address Table: Ethernet switches maintain a MAC address table, also known as a switching table or CAM (Content Addressable Memory) table. This table keeps track of the MAC addresses associated with each device connected to the switch’s ports. When a packet arrives, the switch checks the MAC address table to determine the outgoing port based on the destination MAC address.
- Learning Process: When a switch receives a packet from a device on a particular port, it learns the source MAC address of the packet and associates it with that port in the MAC address table. This process enables the switch to build a mapping of MAC addresses to specific ports.
- Broadcasts and Unknown Unicast: If the destination MAC address is not found in the MAC address table, the switch will broadcast the packet to all ports (except the incoming port). This is done to allow the destination device to respond and update the switch’s MAC address table.
- Efficient Communication: As devices communicate with each other, the switch updates its MAC address table based on the source MAC addresses of incoming packets. This ensures that future packets destined for those devices are efficiently forwarded only to the relevant port.
Benefits of Ethernet Switching:
- Efficient use of network bandwidth: Switches create dedicated communication paths, reducing network congestion.
- Low latency: Switches forward data directly to the destination, minimizing delays.
- Enhanced security: Isolates devices in separate VLANs for improved security and network management.
- Improved performance: Reduces collisions compared to traditional Ethernet hubs.
- Scalability: Switches can be easily added to accommodate more devices.
Ethernet switching has become the foundation of most modern LANs, providing fast and reliable communication between devices. It has largely replaced the use of Ethernet hubs, which operate at a lower level and result in higher collision rates and less efficient communication.