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What Is A Bridge In Computer Network? How They Improve LAN Performance

In computer networking, organizing and managing network traffic is essential to ensure smooth communication between devices. Bridges are one of the core components in achieving this, especially in local area networks (LANs).

Shivangi Vatsal

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What Is A Bridge In Computer Network? How They Improve LAN Performance

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Table of content:

What is a Bridge in Computer Network?
Why Use a Bridge in Networking?
Functions of a Bridge in Computer Network
How Does a Bridge Work?
Types of Bridges in Computer Network
Bridge vs. Router: Key Differences
Advantages and Disadvantages of Using Bridges
Practical Applications of Bridges
FAQs on Network Bridges

A bridge in computer networks is a fundamental device that helps segment and manage network traffic, making it easier to maintain and scale networks efficiently. This article will talk about what a bridge is, its purpose, the types of bridges, and how they function within a network.

What is a Bridge in Computer Network?

A bridge is a device used to connect two or more network segments, allowing them to function as a single network. Bridges operate at the data link layer (Layer 2) of the OSI (Open Systems Interconnection) model. Unlike routers, which connect different networks, bridges are designed to connect segments within the same network, making them suitable for LANs.

A bridge examines each data packet’s destination address and either forwards or discards it based on that address, ensuring that data only reaches the intended segment.

Why Use a Bridge in Networking?

Bridges are primarily used to enhance network performance and organization. Here’s why they are essential:

Reduce Network Traffic: By segmenting a network, bridges help reduce unnecessary data transmission across the entire network.
Increase Network Scalability: Bridges make it easier to add new devices to the network without creating too much congestion.
Enhance Security: Bridges can filter data packets and limit traffic to specific segments, adding a layer of control and security.
Improve Data Flow: Dividing a network into segments optimizes data flow, as data is only sent to relevant sections.

Functions of a Bridge in Computer Network

The primary functions of a bridge include:

Function	Description
Traffic Filtering	Bridges filter data packets based on MAC addresses, allowing only necessary traffic through.
Forwarding Data	Bridges forward data packets only to the destination segment, improving data flow and efficiency.
Network Segmentation	Bridges split a larger network into smaller segments, reducing congestion.
Collision Reduction	By segmenting networks, bridges reduce collisions that occur in high-traffic networks.

How Does a Bridge Work?

A bridge maintains a MAC address table that records the addresses of all devices within each connected segment. Here’s a simplified overview of how a bridge operates:

Learning Phase: When a data packet arrives, the bridge learns the device’s MAC address and stores it in the MAC table.
Filtering and Forwarding: The bridge examines the destination MAC address of each incoming packet. If the destination is within the same segment, it discards the packet; if it’s in a different segment, it forwards the packet to the correct segment.
Loop Prevention: To prevent data loops, bridges use the Spanning Tree Protocol (STP), which identifies and disables redundant links.

Types of Bridges in Computer Network

Bridges come in several types, each designed to meet specific networking needs. Here’s an overview of some:

Type	Description	Key Feature
Transparent Bridge	The most common bridge type; operates invisibly and forwards data based on MAC addresses.	Uses MAC address filtering
Source Routing Bridge	Determines packet routes based on information provided by the sender’s device.	Used in Token Ring networks
Translational Bridge	Connects different types of network architectures, such as Ethernet and Token Ring.	Enables cross-architecture connectivity

1. Transparent Bridge

Transparent bridges are commonly used in Ethernet networks and work by learning device addresses. They don’t require any configuration by the network administrator, making them easy to implement.

2. Source Routing Bridge

Source routing bridges are used in networks where the sending device determines the route for the data. This bridge type is prevalent in Token Ring networks.

3. Translational Bridge

Translational bridges connect networks with different architectures, such as Ethernet and Token Ring, by translating protocols between the two network types.

Bridge vs. Router: Key Differences

Aspect	Bridge	Router
OSI Layer	Data Link Layer (Layer 2)	Network Layer (Layer 3)
Purpose	Connects segments within a network	Connects different networks
Data Filtering	Filters based on MAC addresses	Routes based on IP addresses
Loop Prevention	Uses Spanning Tree Protocol (STP)	Uses routing protocols (e.g., OSPF, BGP)
Primary Use	Suitable for LANs	Suitable for LANs and WANs

Advantages and Disadvantages of Using Bridges

Advantage	Description
Reduces Traffic Congestion	Segments a network, reducing unnecessary traffic across segments.
Enhances Security	Limits data access to specific segments, increasing control over traffic.
Cost-Effective Solution	Bridges are generally more affordable than routers for LAN segmentation.

Disadvantage	Description
Limited to Single Network	Bridges work within a single network and are unsuitable for wide-area networking.
Not Scalable for Large Networks	Not ideal for large networks due to limited routing capabilities.
Slower Data Processing	Bridges can be slower than routers because they process data based on MAC addresses.

Practical Applications of Bridges

Bridges are used in various networking scenarios, including:

Office Networks: Used to manage internal traffic and connect multiple departments.
Campus Networks: Large campuses use bridges to segment their networks, creating smaller, manageable units.
Home Networks: Some home setups with multiple access points use bridges to improve performance and manage bandwidth.

FAQs on Network Bridges

What is a bridge in a computer network?

A bridge is a device that connects network segments, allowing them to communicate as one network.

What is the purpose of a bridge in networking?

Bridges help reduce network congestion by segmenting traffic and improving data flow between segments.

What are the main types of bridges in a network?

Transparent bridges, source routing bridges, and translational bridges.

What is a transparent bridge?

A bridge that operates without user configuration, filtering data based on MAC addresses.

What is the difference between a bridge and a router?

A bridge connects segments within a network, while a router connects different networks and routes data based on IP addresses.

How does a bridge prevent network loops?

Bridges use the Spanning Tree Protocol (STP) to identify and disable redundant links, preventing data loops.

Where is a bridge typically used?

Bridges are commonly used in local area networks (LANs) for segmenting traffic.

What is the function of a source routing bridge?

It allows the sending device to determine the route of a data packet, commonly used in Token Ring networks.

How does a bridge improve network performance?

By filtering and segmenting data, bridges reduce network congestion and improve data flow efficiency.

Can a bridge connect different types of networks?

Yes, a translational bridge can connect networks with different architectures, such as Ethernet and Token Ring.

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Edited by

Shivangi Vatsal

Sr. Associate Content Strategist @Unstop

I am a storyteller by nature. At Unstop, I tell stories ripe with promise and inspiration, and in life, I voice out the stories of our four-legged furry friends. Providing a prospect of a good life filled with equal opportunities to students and our pawsome buddies helps me sleep better at night. And for those rainy evenings, I turn to my colors.