CCNA Practical Studies Part 2: Simulation Software

When you are on a tight budget and you want to get your CCNA, software simulators are the way to go. Aside from building your own CCNA lab, one can also rent rack time online, which we will talk about in part 3 of this series.

Here are great alternatives I found:

1. Boson's NetSim for CCNA
   
2. RouterSim's CCNA Network Visualizer
   
3. Dynamips Router emulator
   

Special note: Dynamips is a hardware emulator which allows actual IOS images to be loaded and run on it. It's free, but needs a little extra memory and processing capacity on the host that it runs on. The other two alternatives cost $249 and $229 respectively.
So check them out and your fit.