SMC Networks SMC7204BRA manual Configuring Bridging

Configuring Bridging

On the receiving network, a LAN protocol such as Ethernet takes over, helping the packet reaches its destination.

When the bridge does not recognize a packet's destination hardware ID, it broadcasts the packet through all of its interfaces – to each network it is attached to.

Note: Bridges vs. Routers : The essential difference between a bridge and a router is that a router uses a higher-level protocol (such as IP) to determine how to pass data. IP data packets contain IP addresses that specifically identify the destination computer. Routers can read this information and pass the data to the destination computer, or determine which next router to send the data to if the destination is not on a connected network. Bridges cannot read IP information, but instead refer to the hardware ID of the destination computer, which is also included in data packets.

Hardware IDs are unique numbers that manufacturers assign to each piece of hardware they sell. A bridge learns to recognize the hardware IDs accessible through each of its ports. When it receives a packet, the bridge simply forwards the packet through the port it associates with the given hardware ID, or through all its ports if it does not recognize the ID. The hardware ID is often referred to as the Media Access Control (MAC) address. Routers are considered more intelligent and flexible devices than bridges, and often provide a variety of security and network administration services based on the IP protocols.

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