differences between HUB, SWITCH & ROUTER?

[Ajsie]

Hi!

What is the main and the practical differences between a hub, a switch and a router?

I know the simplified version:

Hub: makes a lan between computers for sharing files or playing games for example.
Switch: a better hub?
Router: Providing two or more computers having an internet connection.

But does someone know little bit more than this...thx beforehand!

Ps. Is it possible to provide internet for many computers with a hub?

[YeOldeStonecat]

You pretty much have it right.

Removed your other post BTW, please don't repeat posts in multiple forums.

A hub is simply a dumb repeater. It's primary use it to tie together computers into a local area network. Any information sent from one computer gets repeated to all computers, in hopes that one of them is the one it meant to communicate with. As you can see...get a lot of computers on a hub, and traffic can become congested. It's all "shared" bandwidth. Hubs pretty much aren't used anymore, considered old "extinct" technology.

A switch performs the same role as a hub, but does it in a much more efficient way. It basically is a hub, with a traffic cop directing traffic. It memorizes all the computers plugged into it using the MAC of each network card. Then...when one computer wants to talk to another computer, that packet is directed only to that other computer. So it doesn't clog up the rest of the network with un-necessary chatter. Each connection is dedicated...full speed. Years ago, switches were prohibitively expensive, and hubs were cheap. Now...switches have come down so much in price, there's just no reason to use an old slow hub.

Routers...a router connects one network to another. Historically routers have 2x ports on them, one for the LAN, one for the WAN. Used to be mainly used in "big expensive corporate networks"...like to connect to a T-1 or larger, connect satellite offices to the main office, etc. With the explosion of broadband lately, the term "router" has been used to refer to these "all in one" boxes that often have a router, a built in 4 port switch, and often the DSL or cable modem itself....so 2 or 3 devices in one physical box that is loosely called a "router". These routers are used as gateways. They still connect one network (your home LAN) to another network (the internet). And also provide a basic firewall protection in how they do that job...NAT.

Technically you can provide internet access to many computers using only a hub. Have one computer act as a proxy server of sorts, 2x network cards, 1x to the WAN connection, the other to the hub, which all the other computers are plugged into.

[objohn]

hub = dumb repeater, all traffic goes to all ports - 1 collision domain, 1 broadcast domain
switch = traffic is only sent to the ip address it is meant for - switch has mac address table to idenify this. 1 collision domain per interface, 1 broadcast domain

router = breaks up networks - routes information between one subnet and another - 1 broadcast domain per interface, 1 collision domain per interface.

[Sid]

Routers...a router connects one network to another.
Hey StoneCat, correct me if I'm wrong but wouldn't that be a bridge?

[YeOldeStonecat]

Hey StoneCat, correct me if I'm wrong but wouldn't that be a bridge?

Well, you're not wrong. The two (routers and bridges) often overlap in function. Bridges can also span topologies...example...ethernet to wireless devices, or home phoneline adapters, even DSL modems. But bridges usually don't care what they're moving, often different protocols can pass through. Kind of like a dumb repeater.

Whereas routers have the ability to route traffic, filtering and forwarding, etc. And usually just ethernet to ethernet in the pure sense.

There is a lumped term out there often used..."Brouters".

[objohn]

Someone has read the Networking Essentials book then!!!!!!