Port forwarding through VPNs and proxies

Everything a VPN or proxy normally does is outbound: you initiate a connection and it is relayed out. Port forwarding is the opposite — you want someone on the internet to initiate a connection to a service running on your machine: a game host, a BitTorrent seedbox, a self-hosted app, a peer-to-peer node. That requires a public IP with an open, reachable port pointing back to you, and behind a VPN, a proxy, or your ISP's CGNAT, you usually do not have one. Incoming connections hit the shared exit and have nowhere to go, because the exit does not know which of its many users the packet is for.

This is why "my torrent client shows no incoming connections" or "friends can't join my server" is such a common complaint once a VPN is involved.

Port forwarding on a shared-IP VPN means the provider maps an inbound port on a shared exit to one specific user. It is genuinely useful for seedboxes and self-hosting, but it became an abuse magnet: forwarded ports on shared IPs were used to host malicious services, and the resulting complaints and legal pressure led many big VPNs — including some that once championed the feature — to remove it entirely. So the honest state of play is that inbound port forwarding is increasingly rare on commercial VPNs, and where it exists it is often on shared IPs with the reputation risks that implies.

Ordinary proxies do not solve this either: a forward proxy is an outbound relay, not an inbound listener. What you actually need for reliable inbound is an address that is yours, with a port you control.

The dependable answer is a public IP you control, and there are two clean routes. First, run your service on a VPS (or a WireGuard tunnel back to one) where you own the firewall and can open any port directly — this is how most self-hosting is actually done and it sidesteps CGNAT entirely. Second, use a dedicated / personal IP: one address reserved for you, which — unlike a shared exit — can sanely be mapped to your service and whitelisted, without the ambiguity of a pool shared by thousands.

To be straight: the s4m VPN is built for private outbound access on a no-logs, RAM-first design, not as an inbound hosting service, so for a publicly reachable port the right tool is your own VPS with a dedicated IP rather than a shared VPN exit. That combination gives you a stable address and full control over which ports are open — the actual requirement behind every port-forwarding question.