Network Bridge: Advantages and Disadvantages

This page explores the advantages and disadvantages of network bridges. It details the benefits and drawbacks of using bridges in a network, along with a basic explanation of what a network bridge is.

What is a Network Bridge?

A network bridge is a networking device that uses a bridge table (also known as a forwarding database) to transmit frames across different network segments. Unlike a hub, which simply broadcasts traffic, a bridge selectively broadcasts traffic from one network segment to another and manages that traffic intelligently. It operates at the data link layer (layer 2) of the OSI model.

Figure 1: Network bridge connecting two different LAN segments.

Benefits or Advantages of Network Bridges

Here are the main benefits of using network bridges:

• Extension of Physical Network: Bridges allow you to extend the physical reach of your network.
• Reduced Network Traffic: By segmenting the network, bridges help reduce overall network traffic.
• Separate Collision Domains: Bridges create separate collision domains, isolating traffic and preventing collisions from propagating across the entire network.
• Increased Bandwidth: Because bridges create separate collision domains, individual nodes have more available bandwidth since fewer nodes share a collision domain.
• Reduced Collisions: By isolating traffic, bridges inherently reduce the number of collisions on the network.
• Interconnection of Different Architectures: Some bridges can connect networks with different architectures and media types, providing interoperability.

Drawbacks or Disadvantages of Network Bridges

While bridges offer numerous advantages, they also have some drawbacks:

• Slower Than Repeaters: Due to the filtering process, bridges are generally slower than repeaters. Repeaters simply amplify the signal; bridges analyze the traffic before forwarding it.
• Broadcasts Not Filtered: Bridges do not filter broadcast traffic. Broadcasts are still forwarded across all connected segments.
• More Expensive Than Repeaters: Bridges are typically more expensive than repeaters due to their increased complexity and functionality.