I wanted to make some ICMP rules on my own, even though I could just have easily gone with the Core defaults. This way better (hopefully) my knowledge on what they're all about I will have to go through them carefully and look for duplicates. I have already found a couple. Feel free to point out anything that looks odd. I'm certainly no expert at this and it's a long, painstaking process to create and fine-tune these rules, so mistakes and incomplete rules are possible, if not likely.