Let's say that a packet I sent requesting for a https server successfully reaches my target (NAT) router.
The router receives it and through port-forwarding/triggering policies, it knows it has to send to Server-1 with IP address 192.168.0.100 at port 443. But the packet that it received has a L3-Encapsulation of Source Router Public IP(ME) and Destination Router Public IP(THEM). I know that it encapsulates the packet with a new frame, which is a new Source Mac and Destination Mac to send through the LAN and find the correct device. But I've heard the L3-Encapsulation do not change. Is that true?
Does that mean server-1 receives a packet that will just have the old L3-Encapsulation that has two public IP Address, or does it change to its own private IP which is 192.168.0.100 and the router's private IP of 192.168.0.1?