Thread: The Differences between a Hub, Switch and a Router

You may know phrase hub, switch or router when somebody was talking about their work. You may be surprising which right device for your network is and what differences between devices are. Answer for this is explained here.

Hub

A hub is a machine that attaches all you networked devices like PCs and printers jointly through a common shared point of access. It will generally contain four or more RJ45 ports. RJ45 ports are utilized with network cables. The general network cable in use is Category 5 or Cat5. The connector on ends looks like a little bigger phone jack. A hub attaches all devices on its ports jointly. When data arrives at one port, it is sent to other ports so that all devices can see all information, generally called packets. When utilized in a huge environment this is not capable as all packets are being sent to all devices on network causing traffic and collisions.

Switch

it is same to a hub and servers usually similar reason but is a bit smarter. It filters and forwards packets on similar network thus they go to where they are wanted and not to all device. As a frame comes into switch, switch saves originating MAC address and originating port in switch's MAC address table. The only time you will see traffic from other devices is when it is going to the address of PC.

Router

this forwards data packets to their destinations through a procedure called routing. It moves data between two separate networks like home network and internet. A router talks with other routers using routing protocols and then makes and maintains a routing table to keep track of what device is where. Routers utilize protocols like ICMP to talk with each other and organize best route between any two hosts

HUB:
A hub is very "unintelligent". Every single signal/packet/bit/whatever that is placed on the network wire (cat5, coax, whatever), is blasted out every active port on the hub. In other words, every computer on a hub sees every computers data that is sent to the hub. In order for this to work correctly, every single computer/device connected to the hub must be running at the same speed and duplex. If 99 computers have a 10/100 Mbps network card, and 1 computer has a 10 Mbps network card, then all other 99 computers will renegotiate their speeds to 10 Mbps. This is because all of these computers are within the same "collision domain".
SWITCH:
The switch is somewhat more intelligent than the hub. Every port on the switch is its own collision domain. So the fact that all your computers have to have the same speed and duplex, is only true as far as the switch port. In other words, you would take all your 10/100 Mbps users and your 10 Mbps only users, and stick them on 2 different ports of the switch. This would cause all the 10/100 users to work at 100 Mbps with no interference from the 10 Mbps people. Dont worry, the 100 Mbps people will still be able to talk to the 10 Mbps people just fine
ROUTER:
Ok, now things begin to get somewhat complicated. The switch may be fantastic, but it has one weakness. It only operates with the computers on the same LAN. It isnt smart enough to send data out to the internet, or across a WAN. In order to do that, you have to have a router. The router is the device which is smart enough to route data from the LAN to the internet, or to your ISP, or to your WAN, or even to another LAN.