What are Bridges in Computer Network?

Bridges are used to connect two subnetworks that use interchangeable protocols. It combines two LANs to form an extended LAN. The main difference between the bridge and repeater is that the bridge has a penetrating efficiency.

Working of Bridges

A bridge accepts all the packets and amplifies all of them to the other side. The bridges are intelligent devices that allow the passing of only selective packets from them. A bridge only passes those packets addressed from a node in one network to another node in the other network.

A bridge performs in the following aspect −

• A bridge receives all the packets or frame from both LAN (segment) A and B.
• A bridge builds a table of addresses from which it can identify that the packets are sent from which LAN (or segment) to which LAN.
• The bridge reads the send and discards all packets from LAN A sent to a computer on LAN A and that packets from LAN A send to a computer on LAN B are retransmitted to LAN B.
• The packets from LAN B are considered in the same method.

Types of Bridges

There are generally two types of bridges which are as follows −

Transparent Bridges

It is also called learning bridges. Bridge construct its table of terminal addresses on its own as it implements connecting two LANs. It facilitates the source location to create its table. It is self-updating. It is a plug and plays bridge.

Source Routing Bridge

This sending terminal means the bridges that the frames should stay. This type of bridge is used to prevent looping problem.

Uses of Bridges

The main uses of bridges are −

• Bridges are used to divide large busy networks into multiple smaller and interconnected networks to improve performance.
• Bridges also can increase the physical size of a network.
• Bridges are also used to connect a LAN segment through a synchronous modem relation to another LAN segment at a remote area.