Bridges

Network Bridging
A Bridge is a networking device responsible for connecting two or more networks together. Segments connected by a bridge can be comprised of one or more PCs. Bridges aren't as commonly used in networking anymore but are still commonly found among medium sized networks.

Bridges behave similarly to switches in that they will learn which port a device is connected to and actively switch traffic to that port. Separate ports on the bridge will create their own separate collision domains. However, multiple devices are connected to a bridge via Hubs. Because of this all computers connected to each hub are kept within their own collision domain, meaning that when a computer attempts to send data through the network it only has to compete with the other computers within the domain of that Hub.

Different Types of Network Bridging
Bridges are used in network bridging, of which there a three different types,
 * Simple Bridging
 * Multiport Bridging


 * Transparent Bridging.

Simple Bridging
Simple bridging is used to connect two networks together using a network bridge. Simple bridging operates by deciding whether of not to forward data from one network to another frame-by-frame. Simple bridging utilises a store and forward method of operation.

Multiport Bridging
multiport bridging, like simple bridging uses a store and forward method of operation and behaves similarly to a simple bridging, however a multiport bridge can connect multiple networks as opposed to just two.

Transparent Bridging
A transparent bridging can also be used to connect multiple networks and also multiple bridges together. Transparent bridging locates and stores the mac addresses of the devices in the network and filters data passing through so that it can send it only to the implied destination as opposed to all devices.