icroyal wrote: I would spend a bit of time working with it. While I doubt you'll see any questions regarding key differences between main mode and quick mode on the exam, it is still good to know it. Know the differences such as Main Mode creating the ISAKMP SA (Main Mode) that is used to send data over the IPSEC SA (quick mode). Know the different protocols that are used in both. Here is a good site that will show you the steps that are in both Main Mode and Quick Mode. It will then go on to tell you what protocols and steps are used to complete both modes. It is a well written article that will probably help you.http://www.microsoft.com/technet/community/columns/cableguy/cg0602.mspx