Guide
8 min readJun 16, 2026

How to Improve NAT Type After a Bad Test: Router, VPN, and FRP Options

After a bad NAT type test, choose the right fix: router settings for real NAT changes, VPN for the quickest workaround, or FRP for specific ports.

Which NAT Fix Should You Try First?

Method 1: Change Router Settings

Start here if you can log in to your router. This path is most likely to produce a real local NAT improvement, but it only works when your router is the final NAT device and has usable public reachability. CGNAT at the ISP or double NAT from another router can prevent local rules from receiving unsolicited inbound traffic.

Try UPnP first

UPnP lets games and consoles request temporary port mappings automatically. It is convenient on a trusted home network, but keep router firmware updated and avoid enabling it on untrusted shared networks.

Use port forwarding for known ports

If the game or app documents its TCP or UDP ports, reserve a stable LAN IP for your device and forward only the required ports. Wrong protocol, wrong local IP, or a second NAT layer will make the rule fail.

Use DMZ only as a fallback

DMZ can expose one device more broadly. It may help a dedicated console, but it is risky for a general-purpose PC. Prefer UPnP or narrow port forwarding first.

Check CGNAT and Double NAT

If the router WAN address is private, shared, or different from your public IPv4, your ISP may be using CGNAT. If an ISP gateway, mesh router, or another router sits in front of your main router, you may have Double NAT. Ask your ISP for a public IPv4, or use bridge or AP mode so only one device routes, then retry UPnP or port forwarding.

Not sure whether CGNAT or double NAT is blocking your router changes? Check both before you keep tuning local settings.

Method 2: Use a VPN Workaround

A VPN does not change your home router's NAT. The Moderate NAT feature can make it easier to join or host multiplayer games by allowing direct peer-to-peer connections. Port forwarding lets other players reach a game or self-hosted service through a configured inbound port.

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Method 3: Use FRP Port Tunneling

FRP forwards a port on a public server to a game or service on your home network. Other people can then connect through the public server, even when CGNAT or double NAT blocks router port forwarding. It works best for self-hosted games and services with known TCP or UDP ports. You need a public-IP server and basic networking skills, and it may not help games that rely on platform relays or dynamic matchmaking.

Which Method Should You Choose?

GoalBest methodWhy
Actually improve your local NAT typeRouter settingsUPnP, port forwarding, and DMZ change how your own router handles inbound traffic.
Improve everyday multiplayer without router changesProton VPN Moderate NATIt is designed for direct peer-to-peer connections; switch to port forwarding only when hosting needs inbound traffic.
Expose a known local service through a public IPFRP tunnelA public server can forward a specific external port back to your local program.

NAT Type Improvement FAQ

Can I actually change my NAT type?

Yes, if you control the router and have a usable public IP address. UPnP, port forwarding, or other router settings can change how your local network handles inbound traffic. If CGNAT or another upstream router controls the connection, changing your home router alone may not change the result.

Which VPN should I use for gaming or hosting?

Use Proton VPN's Moderate NAT for ordinary multiplayer and peer-to-peer rooms. If your game or app accepts one configurable inbound port, use Proton port forwarding instead. Choose PureVPN's port-forwarding add-on when a self-hosted server needs several selected ports. Moderate NAT and port forwarding cannot be active together.

What should I do if I am behind CGNAT?

First, ask your ISP for a public IPv4 address or use native IPv6 when the application supports it. If neither is available, use a VPN with port forwarding for a simpler workaround or FRP for a specific inbound port. Repeating local port-forwarding rules will not bypass ISP-side CGNAT.

Test Again After Each Change

Change one thing at a time, restart the game or device when needed, then run the NAT test again. If router settings do not work and CGNAT is present, stop repeating the same local rules and choose either a VPN-style workaround or a public-server tunnel.

Check NAT Type Now →
Official feature sources

These official pages were used to verify the Moderate NAT, port-forwarding, refund, and FRP details above. Features and policies can change, so check the latest information before choosing a service.

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