Changes

# At this point you should be able to understand any iptables rules you'll see in this course, including the default ones in CentOS. If you see a rule you don't understand - you can delete it and see what happens. But if you do that - spend some time figuring out what that rule did and why you needed to delete it. It was likely there for a good reason.

Finish the exercises, and record any information you feel you'll need to remember to solve problems like this in the future (e.g. in a practical test).