What is a network bridge?

A network bridge is a device or software that connects two or more separate computer networks together, allowing them to communicate and share resources. It operates at the data link layer (Layer 2) of the OSI model and is used to extend the reach of a network by forwarding data packets between different network segments or LANs (Local Area Networks).

A network bridge works by examining the destination MAC (Media Access Control) address of incoming data packets and forwarding them only to the appropriate network segment. It creates a single logical network by transparently connecting multiple physical networks, effectively expanding the network's coverage area.

Bridges are typically used in scenarios where there is a need to connect different types of networks, such as Ethernet and Wi-Fi, or to segment a large network into smaller, more manageable segments. They can also be used to improve network performance by reducing network congestion and improving overall network efficiency.

In addition to connecting networks, bridges can also provide additional features such as filtering and security. They can filter out unwanted traffic or malicious packets, ensuring that only valid data is forwarded across the network. Some advanced bridges also support VLAN (Virtual Local Area Network) tagging, allowing for the creation of virtual networks within a physical network infrastructure.

Overall, a network bridge plays a crucial role in connecting and expanding computer networks, enabling efficient communication and resource sharing between different network segments or LANs.