This is a physical network gadget that joins together numerous networks by use of the wired or wireless connection. It is a device that has interfaces in numerous networks and whose function is copying packets from a network to another. The level at which routers are operated is the Network layer which is the third layer of the OSI model. There are various types of interfaces like Ethernet and DSL. To create a routing table, a router makes use of one or more routing protocols. Information from the routing table is then used by the router to make intelligent selections on the choice of packets to copy to a particular interface, a process called routing. An example is an Internet protocol which is used for internet connection at home. The IP router connects the home area network to the Wide-Area Network or the WAN of the internet.
Within one Local-Area Network (LAN), several ports are linked using a small device that is called a switch. While the routers are operated at the third layer of the OSI model, the switch functions at the second level of OSI which is the Data Link layer. A network switch stores MAC addresses for every device that is linked and evaluates every frame that has to go through it. The network switch also checks the destination of the MAC. The network switch, unlike the network hub, has more intelligence.
A switch contains multiple ports in a single network and the function is copying frames from one port to the other. The switch is influenced by the destination MAC address to make decisions on where the frame will be copied. If a destination is not recognized by the switch, the switch does not know where to copy a frame and what it does is transmit that frame to all the ports. The switch is closely related to the Bridge which is a double-port switch that has run out of the market because of the lack of its need.
Network Interface Cards
This is an expansion card that is also called network adapter, network card, or NIC. The Network Interface card is installed into the Personal computer (PC) to enable connection to the Local Area Network. The types of Interface cards include; the Ethernet card, the wireless network interface card and the Token Ring interface card.