This course is all about IOS security and all features that you can find to harden your router and switch and use your router as a firewall so that you don't have to invest your precious dollars on a firewall device!
I have explained all commands in detail so that you can easily get a grab on that feaure. If you cannot find a feature, this means either it is obsolete and a better feature replaces that or I have forgotten to include it. In the latter case, I will be more than happy if you let me know what you want and I will add it to the curriculum.
I have used GNS3 for the simulation. However, you can execute all commands on a real gear without any change.