How to extend or to divide a network?

Question

I try to understand the difference between the Switch, Hub , Bridge , etc ... But I did not really happen.

In the event that I wish to extend my network or divide, what material should I use exactly ?

Answer 1

The real difference between these pieces of equipment (at least in terms of extending or dividing) are the way they handle Collisions, and the way they treat Broadcast traffic. I note that you did not mention Routers or other devices at layer 3 or higher, so we will focus on Layer 2 topics.

A Collission Domain is the area of a network where shared media is used, and collisions between multiple senders may occur. Hubs have a single collision domain, so only one host at a time may send data. Bridges that connect 2 segments have two collision domains. Switches however have as many collision domains as they have ports, because switch ports are separated from each other, so that no two ports could suffer a collision (this is called a Micro-Segmented architecture).

For Broadcast traffic, If I send a Layer 2 broadcast (a Frame with the destination MAC address FF:FF:FF:FF:FF:FF) that frame will be forwarded to every machine within the Broadcast Domain. All three types of devices extend the Broadcast Domain of the network. Many switches however can now implement Virtual Local Area Networks (VLANS), which allows an administrator to divide up a Broadcast Domain into smaller parts. Routers also divide Broadcast domains, but I notice you did not mention them.

So in sum, Hubs create large collision domains, and bridges divide the network into separate collision domains. Switches divide the collision domains so much that unless you have a hub mixed in, collisions are almost impossible.

All Layer 1 and 2 devices (hubs, switches, bridges, etc) extend the Broadcast domain, unless a Routing device is involved, to route traffic between LANs or VLANs. VLANs divide the Broadcast domain into smaller areas, to prevent broadcast traffic from becoming disruptive on the network.

Answer 2

For what purpose.. If you're trying for an exam or course and want to know properly for your own interest too, and you want to know the technicalities..you should look first at what a hub is, then look at what a switch is. Any book will do that. Computer Networking is a very complex subject

What counts also is what kind of product you have.. many people have a product that mixes features like modem-(2 interfaces router wan and lan)-switch, in one, and if you want to extend the network you have, you just plug a switch in the switch and then plug computers into the switch new switch.

If it's a really big network or you want to start controlling things so computers in one subnetwork do/don't communicate with computers in another, then you need a router or VLAN Switch.. ( a VLAN switch may need or be part of a product that has a router built into it too). But some of these things are advanced networking devices that need to be configured.

If you were an admin of a large network and had to extend it.. then bear in mind the hierarchy.. computers plug into switches, switches plug into routers, routers connect to each other. And there'll be a lot of configuration.

If you are talking about your own network and it's not huge then just plug a switch into the switch you have. No configuration required. Not a pricey switch. Just plug and go. All those ports on the NAT router people have, are switch ports.