[Networks] Hub, switch and router

Introduction

Depending on the size and type of network these 3 types of hardware are used: The Hubs, Switches and Routers.

The hardware

The Hub

The hub (hub) is the network hardware, the most basic. It is used for a LAN with a very limited number of machines. It is neither more nor less than 'RJ45 strip' which amplifies the signal network (10/100 Base).

The hubs works at the first layer of the OSI model

The Switch

The switch it works at the first two layers of the OSI model, it distributes data to each t machine, while the hub functionality sends all data to all machines that respond. Designed to work on networks, with a number of machines slightly higher than the hub, it eliminates the possible packet collisions (a collision appears when a machine tries to communicate with a second while another is already in communication with it).

Router

The router allows the use of several classes of IP addresses within the same network. It allows the creation of subnets.

It is used in larger installations, where it is needed to create multiple subnets. When the Internet connection use a RJ45 cable it is necessary to use a router to connect a sub-network to the Internet, because these two classes of connections used are different. They also act as firewall (firewall) to protect the installation.

The Repeater

This amplifies the signal for networks that extend over long distances.