How to Fix "Strict NAT Type" and Open Ports for Peer-to-Peer Servers
What Is Strict NAT Type and Why Does It Break P2P?
Strict NAT Type means your router is blocking inbound unsolicited UDP/TCP packets — the exact type of traffic that peer-to-peer gaming and server communication depends on. When your NAT is Strict (Type 3 on PlayStation, Strict on Xbox, Type D on Nintendo), you can only connect to hosts with Open NAT, severely limiting matchmaking pool size and causing connection timeouts, voice chat failures, and server join errors.
NAT Type Reference Table
| NAT Type | Platform Label | Connectivity | Action Needed |
|---|---|---|---|
| Open | Type 1 / Open / Type A | Full P2P | None |
| Moderate | Type 2 / Moderate / Type B | Most P2P works | Optional improvement |
| Strict | Type 3 / Strict / Type C/D | Very limited P2P | Fix required |
How to Fix Strict NAT Type
Fix 1 — Enable UPnP on Your Router
Log into your router admin panel (typically at 192.168.1.1 or 192.168.0.1 in your browser). Navigate to Advanced → UPnP and enable Universal Plug and Play. This allows games and P2P apps to automatically open required ports. Save and restart your router.
Fix 2 — Assign a Static LAN IP to Your Device
Port forwarding requires a fixed LAN IP. In your router's DHCP settings, find your device's MAC address and create a DHCP reservation so it always receives the same IP (e.g., 192.168.1.100).
Fix 3 — Forward Required Ports
In your router's Port Forwarding section, add rules for your application:
- eFootball / PES: UDP 3478, 3479, TCP 80, 443
- Warframe: UDP 4950, 4955, TCP 6695
- General gaming: UDP 3074 (Xbox Live), UDP 3659 (PSN)
Set the internal IP to your device's static LAN IP from Fix 2.
Fix 4 — Use DMZ as a Diagnostic Step
Temporarily place your gaming device in the router's DMZ (Demilitarized Zone) to confirm NAT is the issue. DMZ exposes the device to all inbound traffic. If NAT Type becomes Open in DMZ mode, port forwarding is the correct fix — remove DMZ and configure specific ports instead.
Fix 5 — Contact ISP About CGNAT
If UPnP and port forwarding don't change your NAT Type, your ISP may be using Carrier-Grade NAT (CGNAT) — a double NAT that no router setting can fix. Contact your ISP and request a public IPv4 address or ask about their IPv6 gaming solution.
Verification
✓ How to Confirm the Fix Worked
Restart your router and device fully after making changes. Check NAT Type in your game's network settings or run an external port check at canyouseeme.org. An Open or Moderate NAT Type confirms success. For server-side P2P apps, check logs for successful inbound handshakes.