Zero trust - just configure the default rule to block any traffic. Above the default rule, create rules for the traffic which should be allowed. Thats all.
Thanks for the replies guys. Appreciate it. I just ran my first class last week and my timing was pretty close to what John put in the Timing guide. - Had to do a ton of Demo's and examples to stretch things out.. Day 1 - Mod 1-4 Day 2 -5 spot on ...