A few friends and I want to run some kind of CTF competition in which we both have identical OSes that we can attack and defend as teams/individuals.
I was looking on the web and I found some good stuff like Metasploitable and some stuff on vulnhub.com
I'm basically looking for any advice as to what the best way to implement this thing is and whether there are any other cool goodies like the above mentioned.
How would you set this competition up? What would you make the goals? How much time should we have to secure the system and how much time should we have to attack? Any advice is welcome. We are very novice to computer security (but all work in IT) and just need an idea of how to start it and how to grade it.