On Wednesday, 22 July 2020 at 16:14:24 UTC, wjoe wrote:
When receiving packets, the IP header contains the destination address of your public IP (the router), which it will translate to the local address according to the port forwarding setup.
Pardon me, I meant to say according to the current routing table rules. Port Forwarding forwards all packets that match the defined criteria to the specified PC in the network. A port forwarding rule isn't required for NAT to work. Sender and receiver both need to send a packet to each other. This will cause the router to add a rule and expect an answer on that port from the destination address. When this packet arrives before the rule has been made it will be dropped (unless a port forwarding rule exists), so several packets may need to be sent for a successful punch-through.
