Network software/Tools to help me learn networks better?

[Mikoyan]

Hey people im wondering if there is such a thing..I would love if there was software that can emulate networks so I can put my own servers, routers, firewalls and add my rules and test my dummy network..

We had software like this at my university but I am taking an interest in networks and rather that destroying my companies network I would like it if there was such software that emulates it?

Any help would be greatly appreciated!

Thanks

Herman

 

[Mikoyan]

thanks for the feedback will check these out..