Networking devices:

Hubs, Switches, Routers .

HUB: Hub is a multiple Repeater its work on physical layer of OSI model it as 8 to 24 ports .Hub is a centralized device provides communication among systems when we have more than 2 computers we need to have a device called hub to interconnect.

Types of Hub:-

1)    Active HUB :- its required external power and its Regenerate the signal

2)    Passive HUB: - it doesn’t required and DC power.

3)    Smart HUB: - its provide Monitoring also.

Disadvantage of a Hub:

When we want to transfer some data from one system to another system. If our network has 24 systems the data packet instead of being sent only to the destined system it

Is being send to all the network participants. (i.e. 24 systems.)Hubs follow broadcasting.

SWITCH: Switch is a network Device which provides switching in a network. Its work on Data link Layer of OSI model .It is an advanced version over a Hub.

Advantage of a Switch:

The main benefit of switch is Unicasting. Data packets are transmitted only to the target computer instead of all .Switch maintains a table called MIT (Mac Information Table.) which is generated as soon as we turn on the switch, which acts like an index table and easy the process of finding the networked system. MIT contains the port no, IP address and MAC address.

ROUTER: Router is a device connects two different networks.

Class A network with Class C network etc.

Routing is a process of communication between two different networks.

Cicso Router