Network Router
Published in: Network Hardware
|
A router is a computer networking device that forwards data packets toward their destinations through a process known as routing. Routing occurs at layer 3 (Network layer) of the OSI seven-layer model.
A router can be used to either connect at least two networks, or to form a mobile ad-hoc network. A special variety of router is the one-armed router used to route packets in a virtual LAN environment. In the case of a one-armed router the multiple attachments to different networks are all over the same physical link.
A router that connects clients to the Internet is called an Edge Router. A router that serves to transmit data between other routers is called a Core Router.
A router creates and/or maintains a table, called a routing table that stores the best routes to certain network destinations and the “routing metrics” associated with those routes. In recent times many routing functions have been added to LAN switches, creating “Layer 2/3 Switches” which route traffic at near wire speed.
Routers are also now being implemented as Internet gateways, primarily for small networks like those used in homes and small offices. This application is mainly where the Internet connection is an always-on broadband connection like cable modem or DSL. These are not “routers” in the true sense, but the terminology has been confused with network address translation.
There are several manufacturers of routers including: