Router NAT Type Guide: UPnP, Port Forwarding, DMZ, and Double NAT
Fix NAT type on a router with the right order: test first, enable UPnP, reserve a device IP, forward required ports, avoid risky DMZ use, and rule out Double NAT or CGNAT.
Router settings can improve NAT type, but only when the router is actually the blocking point. Start with a NAT test, then choose between UPnP, port forwarding, DMZ, bridge mode, or access point mode based on the result. If the upstream path is Double NAT or CGNAT, local router rules alone may not work.
Preparation
Before you begin, gather the following information:
- Router IP address, username, and password (usually found on a label on the back of your router)
- IP address of your gaming device (PC or console)
- TCP or UDP port numbers to forward (if using specific port forwarding)
Router NAT Fix Decision Tree
Use this order instead of changing every router option at once. Each step rules out a specific cause of Strict NAT, port-restricted NAT, or failed inbound connections.
1Run a NAT test first
Confirm whether the issue is Open, Moderate, Strict, port restricted, or symmetric behavior before changing router settings.
2Enable UPnP on trusted home networks
UPnP lets consoles and games request temporary mappings automatically. Restart the game or device after enabling it.
3Reserve a stable LAN IP
Port rules fail when the console or PC gets a new local IP. Use DHCP reservation or a static IP outside the router's automatic pool.
4Forward only the required ports
Use the exact TCP/UDP ports for the game, platform, or server. Forwarding TCP when the game needs UDP will not fix NAT.
5Use DMZ only as a narrow fallback
DMZ exposes one device more broadly. Prefer UPnP or port forwarding first, and avoid placing a general-purpose PC in DMZ.
6Remove a second router layer
If an ISP gateway and your own router both route traffic, use bridge mode on the gateway or access point mode on the second router.
7Check Double NAT and CGNAT
If the router WAN IP is private, shared, or different from the public IPv4, local forwarding may not reach the internet.
UPnP vs Port Forwarding vs DMZ vs Bridge Mode
| Setting | Best use | Risk or limitation |
|---|---|---|
| UPnP | Consoles and games on a trusted home network that need temporary mappings. | Less predictable on buggy routers; not ideal on shared or untrusted networks. |
| Port forwarding | Known game/server ports pointing to one stable device IP. | Wrong protocol, wrong local IP, or Double NAT will make the rule ineffective. |
| DMZ | Temporary troubleshooting or a dedicated console when narrower rules fail. | Broad exposure; avoid using it as the first fix for a PC. |
| Bridge/AP mode | Removing a second NAT layer between ISP gateway and your own router. | May move Wi-Fi, firewall, or login responsibilities to a different device. |
Method 1: Using DMZ (All Ports Open)
This is the simplest method. It opens all ports for the specified IP address.
1Access Router Settings
Enter your router IP address in a browser, then log in with your username and password. Find "Forwarding", "NAT Settings", or "Advanced Settings" in the menu.
2Get Your Device IP Address
For PC Users:
Type "cmd" in Windows search, run as administrator. Type "ipconfig" and press Enter, find "IPv4 Address".
For PS4 Users:
Go to Settings → Network → View Connection Status, find IP Address.
3Configure DMZ
Click "DMZ" in router settings. Enter your device IPv4 address, set DMZ status to "Enable", and click Save.
4Restart Router
After saving settings, restart your router for changes to take effect.
Method 2: Forward Specific Ports
If you prefer to only open ports for specific games (like Call of Duty: Modern Warfare) for security reasons, use this method.
Important: You cannot use both DMZ and specific port forwarding at the same time. If you want to forward specific ports, you must first disable DMZ.
- 1Find Port Numbers
Search for the TCP/UDP port numbers required by your game.
- 2Access Virtual Server
Find "NAT Settings" or "Virtual Server" in your router settings.
- 3Add Rules
- • Enter the port numbers in "Service Port" or "Start Port"
- • Enter your device IP address
- • "Internal Port" can usually be left empty
- • Select protocol type (TCP, UDP, or both)
- 4Save and Restart
Click Apply Settings and restart your router or modem.
When Router Settings Will Not Fix NAT
If UPnP, port forwarding, and DMZ do not change the result, stop adding rules and verify whether another NAT layer sits upstream.
Verify Your NAT Type
After configuring your router, use our free online tool to verify your new NAT type:
Conclusion
By following these steps, your network connectivity should significantly improve. Whether you choose DMZ for simplicity or port forwarding for security, both methods can help you achieve a better NAT type for gaming and online applications.