CISCO Switching Basics : Broadcaste & Collision Domains

2- Broadcaste & Collision Domains : 

2-1- Collision domains: 

   to begin with, it's vital to know that one of the advantages of modern switches is that each port on the switch is considered as a collision domain.
so when a collision is occured, the damaged frame does not pass the interface(not the Hubs' case the damaged frame will be sent to all connected devices).

figure.1 each switch port is collision domain.

   as the figure.1 shows that the switch breaks the network to 4 collision domains, so we can say the switches increase the number of collision domains which is a good thing.
on the other hand, all the ports of a Hub are considered to be 1 collision domain, so hubs do not separate collision domains.

2-2- broadcast domains :

   talking about broadcast domains, you should know that switches do not separate broadcast domains
you may ask WHO does, well Router do.
however if a switch has received a frame addressed with a broadcast destination, then it will forward it out of all interfaces, except the one where the frame was received on.

figure.2 Broadcast domains.








2-3 Sum-up :

to finish with, the following topology may be the best practice.

figure.3 collision & broadcast domains.

   so this is it Guys, hope i covered it up as clear as possible.
Next we will talk about switching Modes

please comment for any notes or questions, propositions...