I'm a beginner in networking things but due to my ISP I can only open a certain range of ports in my router to be accessible from the outside of my network (something like ports 11000-11500).
That means I can't open port 443 to access my reverse proxy from the outside. Is it possible to redirect all traffic that's coming from one of the ports in the range to port 443 of my server?
I haven't found that possibility in my router (Fritzbox 7530) so is there a way to do this on my server (running Fedora Server)?
You can find more information searching for "iptables dnat".
What you are saying here is: in the prerouting table (ie: before we decide what to do with this packet) tcp connections to my IP at the port 11500 must be forwarded to my IP at port 443.