Networking Device

Difference between router, switch, bridges, and hubs including their pinciples






router



A device that connects any number of LANs.
Routers use headers and a forwarding table to determine where packets go, and they use ICMP to communicate with each other and configure the best route between any two hosts.
Very little filtering of data is done through routers. Routers do not care about the type of data they handle.




bridge

A device that connects two local-area networks (LANs), or two segments of the same LAN that use the same protocol, such as Ethernet or Token-Ring.











switch

In networks, a device that filters and forwards packets between LAN segments. Switches operate at the data link layer (layer 2) and sometimes the network layer (layer 3) of the OSI Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs.








hub

A hub is a "unintelligent" broadcast device -- any packet entering any port is broadcast out on every port. Hubs do not manage any of the traffic that comes through their ports. Since every packet is constantly being sent out through every port, you end up with packet collisions, which greatly impedes the smooth flow of traffic on your LAN.


References:
http://www.experts-exchange.com/Hardware/Routers/Q_20381112.html