LAN switching

LAN switching is a form of packet switching used in local area networks (LAN). Switching technologies are crucial to network design, as they allow traffic to be sent only where it is needed in most cases, using fast, hardware-based methods. LAN switching uses different kinds of network switches. A standard switch is known as a layer 2 switch and is commonly found in nearly any LAN. Layer 3 or layer 4 switches require advanced technology (see managed switch) and are more expensive, and thus are usually only found in larger LANs or in special network environments.

Layer 2 switching

Layer 2 switching uses the media access control address (MAC address) from the host's network interface cards (NICs) to decide where to forward frames. Layer 2 switching is hardware-based, which means switches use application-specific integrated circuit (ASICs) to build and maintain filter tables (also known as MAC address tables or CAM tables). One way to think of a layer 2 switch is as a multiport bridge.