What is wrong with my global Rules?
Does allowing port 0 also allows IGMP and mDNS. I have blocked both in global rules
Do I have to allow port 0
Explain this According to Wikipedia
Port 0 - In programming APIs (not in communication between hosts), requests a system-allocated (dynamic) port
0.0.0.0/8 - Current network (Wikipedia is vague and wrong for this)
Using port 0 in firewall rules means any port. The 0.0.0.0/8 addresses means any/all IPv4 addresses, so your first logging rule is why you are seeing logged allowed connections.
For information about port 0
Port 0 and network security
Network traffic sent over the Internet to hosts listening on port 0 can be generated by network attackers or accidentally by incorrectly programmed applications. Reply messages generated by hosts in response to port 0 traffic can help hackers learn more about the behavior and potential network vulnerabilities of these devices.
Many Internet Service Providers (ISPs) block port 0 traffic (incoming and outgoing messages) to guard against these exploits.