Hello networking community! I need a setup where I can forward my server from my private network to another network which has a public ip to forward the server itself to the internet. When a client connects to the server, traffic should get forwarded to my private network somehow. I know that's possible, but don't know how I can achive that.
Came back after a year, got some knowledge. I achieved this setup using WireGuard (+ PersistentKeepAlive) and custom iptables rules on an old laptop with barebones arch install. By masquerading, we loose the source ip when forwarding, and to preserve it we need a L2 tunnel (L2GRE).
Tailscale to connect everything. Then in the public server use a reverse proxy (nginx proxy manager or swag) and point it to the tailscale IP of the server you want out.
Thanks for the reply! I will research it a bit, I still lack tons of knowledge about networking, yet still learning.
The above comment is right, use Tailscale or something similar. If you are interested in knowing more, search up "NAT transversal".
But my experience suggests that those solutions may introduce quite a bit of latency, which is probably not desirable when you are running a game server. If you have IPv6, take advantage of it and let the ADSL2 router connect to your forward server using IPv6.
So, I can receive incoming traffic using IPv6 despite I don't even have a public ip? (nv my ISP doesn't support IPv6)
If you have IPv6 connection and the address starts with "2", then your public address is the IPv6 address.
Nope it just doesn't support it. I tinkered a bit in router config enabling IPv4/IPv6. But didn't get IPv6 address from ISP. Still using ADSL2+