The Difference Between Hubs, Routers and Switches

The networking world revolves around hubs, switches and routers, these are what constitute the great majority of our domestic and business networks today (maybe not so much if more centers!) Let's start with the hubs.

Note: In this article, refer to a layer two and three devices. Without going into many details about the OSI model for networking; Refers to the communication of the physical layer. Layer Two refers to specific hardware address (using MAC) and Layer 3 refers to the logical network address using IP addresses.

Forums - Hubs, also known as repeaters are layer 1 devices that reproduce essentially all network traffic for each active port. This means that if a device on a hub sends information to another device on the network, all devices on the hub must listen to the information and see if it is intended for them. Hubs do nothing in terms of data analysis and decision making, so they are simply layer devices 1. In the networks of the world centers of today are becoming less frequent and are replaced by switches.

Switches - Switches are Layer 2 devices, unlike centers that replicate the traffic for each active port, instead, make decisions based on Layer 2 (MAC address). When a packet enters a switch that has analyzed your destination Layer 2, the switch then check your Mac Address table to see where this machine belongs, if the device is unknown to the switch, then the packet will be flooded all ports (beyond which came on). Collisions do not occur in the switches that each port has its own collision domain.

Routers - routers are layer 3 devices; they analyze network traffic based on your Layer 3 address, or IP address. Routers are used to connect multiple networks together and you have what is called a routing table. This routing table contains information on the various networks and where they are located. Routers are slower than switches in terms of movement of traffic across a network, but this is simply because routers must make decisions about where to send a packet, it can be quite complicated for a router when there are multiple routes to different networks when this happens a router must calculate the cost based on the bandwidth, or how far is the link, for example. The routers are essential for the creation of a vast network comprised of many smaller networks.

So you have fundamental differences between hubs, switches and routers.