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Forwarding Table Layer

Oct 30, 20241 min read

Forwarding Table Layer

  • Switches operate at Layer 2.
  • They use L2 Forwarding Table to manage the forwarding of packets within a local area network (LAN).
  • The table is built using dynamic learning algorithms, where the switch learns the MAC addresses of devices.
  • When the switch knows the destination address, it sends the packet only to the corresponding link/segment.
  • If the destination is unknown, the switch performs flooding.

Layer 3 (Network Layer)

  • Routers operate at Layer 3.
  • They use L3 Forwarding Table (also known as routing tables) to manage the forwarding of packets across networks.
  • Routers use routing protocols (e.g., OSPF, BGP) to learn about the network and make forwarding decisions.
  • Routers always forward packets based on the network layer addresses (e.g., IP addresses) and never broadcast.

Comparison

  • L2 Forwarding Table are used for MAC addresses within a local network, while L3 Forwarding Table handle IP addresses for inter-network communication.
  • Switches handle communication within the same network, while routers handle communication between different networks.

Graph View

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