Terminology » Network Bridge: Advantages and Disadvantages

Network Bridge: Advantages and Disadvantages

network bridge network traffic collision domain data link networking

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.

Bridges

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.