Basic networking components

Network interface cards

NETWORK Interfacing cards is also known as network adopter. the purpose of this card is to connect third party devices with computer system. it having own device driver
to install for working this card.

Repeaters
Repeaters or hubs work at the OSI physical layer to regenerate the network’s signal and resend them to other segments
Primitive hub can be viewed as a multi port repeater
It regenerates data and broadcasts them to all ports

Hubs

Intelligent hubs have console ports, to allow monitoring of the hubs status and port activity.
Passive hubs just repeat any incoming signals to every port available, therefore does not act as a line repeater.
Passive hubs just split signals to multiple ports but do not regenerate the signals, which means that they do not extend a cable’s length. They only allow two or more hosts to connect to the same cable segment.
Active hubs regenerate signals.
Hubs utilize star topology.



Bridges

Has one input and one output
Used to isolate network traffic and computers
Has the intelligent to examine incoming packet source and destination addresses

But cannot interpret higher-level information
Hence cannot filter packet according to its protocol


Routers

Routers are OSI network layer 3 devices
Using interface modules can connect different layer 2 technologies e.g. Ethernet, FDDI, token ring etc…
Routers have the capability to interconnect network segments or entire networks (WANS/MANS).
These devices examine incoming packets to determine the destination address of the data. It then examines its internal routing table to choose the best path for the packet through the network, and switches them to the proper outgoing port.

Switches


fayyaz

A switch is a mufti-port bridge.
It operates at OSI data link layer 2.
It stores MAC addresses in an internal lockup table.
Temporary switched paths are created between the frame’s source destination.
Some Switches have limited layer 3 IP routing capabilities.
Switches can be configured to use V LANS.
Switches support spanning tree protocol to create resilient networks.