Forward port from local system to remote IP | NAT loopback

Ask Fedora
1

I have two interfaces on my system, one with a static public IP and one on a private network.

I have port forwarding working such that if a connection comes in remotely to the public IP, it will get forwarded to an IP:port on the private network.

However, I also want to be able to forward connections originating on the local system to the static public IP to also get forwarded to an IP:port on the private network. I’m just getting connection refused right now.

What sort of sorcery do I need to forward locally initiated traffic to the public IP:port to the private subnet IP:port?

Thank you!

2

This is how it works:

# Port forwarding
sudo firewall-cmd --permanent --zone=${WAN_ZONE} --add-forward-port=\
port=${WAN_PORT}:proto=${PROTO}:toport=${LAN_PORT}:toaddr=${LAN_ADDR}
sudo firewall-cmd --reload

# NAT loopback
sudo firewall-cmd --permanent --zone=${LAN_ZONE} --add-forward-port=\
port=${WAN_PORT}:proto=${PROTO}:toport=${LAN_PORT}:toaddr=${LAN_ADDR}
sudo firewall-cmd --permanent --zone=${LAN_ZONE} --add-masquerade
sudo firewall-cmd --reload

However it’s a dirty hack with certain drawbacks.
Split DNS or IPv6 are better options.