Understanding Global Rules

I have installed Comodo Firewall (not Anti virus) v4.1.150349.920

I go to Firewall → Common Tasks → Stealth Ports Wizard

If I select 2nd option - “Alert to incoming connections …” the Global Rules section has 5 rules
B1) Block ICMP Out From IP Any To IP Any Where ICMP Message Is PROTOCOL UNREACHABLE
B2) Block ICMP In From IP Any to IP Any Where ICMP Message Is 17.0
B3) Block ICMP In From IP Any to IP Any Where ICMP Message Is 15.0
B4) Block ICMP In From IP Any to IP Any Where ICMP Message Is 13.0
B5) Block ICMP In From IP Any To IP Any Where ICMP Message Is ECHO REQUEST

If I select 3rd option - “Block all incoming connections …” the Global Rules section has 4 rules
C1) Allow IP Out From IP Any To IP Any Where Protocol Is Any
C2) Allow ICMP In From IP Any to IP Any Where ICMP Message Is FRAGMENTATION NEEDED
C3) Allow ICMP In From IP Any to IP Any Where ICMP Message Is TIME EXCEEDED
C4) Block IP In From IP Any to IP Any Where Protocol Is Any

Could you help me understand these rules, in particular B1, B2, B3, B4, C2 and C3 or direct me to a link where I can find more??

Any sources of information that adds to the information in the Help File would be gratefully received.

Many thanks. :slight_smile: :slight_smile:

http://www.networksorcery.com/enp/protocol/icmp.htm