What is Bridge

A bridge is a network communication device that is used to connect one segment of the network with another that uses the same protocol.  It operates at the Data link layer of the OSI layers model.  In the Ethernet network, the bridge is also known as IEEE 802.1D.  A bridge process the information at the data link layer of the OSI layers model.  There are two types of the bridging.

• Transparent bridging
• Source route bridging

The main advantages of the bridges include the following.

• Inexpensive
• Self Configuring
• Reduced size of the collision domains.
• Transmits the data based on the MAC address.
• Supports relatively big networks.

Bridges are fast devices for forwarding the data but not as fast as the routers and switches.  A bridge cannot be used as a firewall device as a router.  In the bridged network, the messages are sent to all the nodes and are picked up only by the destined computers.  A bridged when combined with the router, known as a brouter.  Bridges has now replaced the switches and routers.