NAT configuration is rigid – attempted port forwarding and activated DMZ mode.
NAT configuration is rigid – attempted port forwarding and activated DMZ mode.
Hello, I’m facing an issue while trying to play an online multiplayer game. Every time I launch it, I receive a warning that my NAT type is STRICT. I’d like to switch to OPEN or at least MODERATE. I’ve documented everything in detail and tried several fixes below. Can you help resolve this?
Problem – NAT type is strict for Assassin's Creed Unity. What doesn’t work:
- Unable to invite friends; they get the message “You couldn't join the session. Try again later.”
- Works when joining random players in multiplayer missions.
- If a friend without this issue invites me, I can join them too.
Additional notes – Both my friend and I have NAT type strict, so we can’t invite each other. Even if one of us fixes it, we’ll still be able to play together. [6:20 AM]
Solutions I’ve tried:
1) Turn off the Windows firewall completely.
2) Forward all necessary ports on the router.
3) Add inbound rules to allow connections for the ports.
4) Add an inbound rule to let ACU.exe connect.
5) Enable a static IP from Windows, which prevents multiplayer connections altogether.
6) Bind the PC’s MAC address to the router’s IP (static like 192.168.0.102).
7) Turn on DMZ mode and enter the 102 IP address.
8) Disable and then enable UPnP on the router (default is enabled).
9) Used a VPN to connect from different regions (UK, Canada).
10) Disabled SPI firewall on the router.
11) Asked my ISP to check for issues and confirm ports are open.
12) Tried using a hotspot instead of home Wi-Fi. Same problem continues.
13) Combined several fixes in different ways; some were enabled, others disabled.
It’s either that I can’t connect online at all, or when I can, the NAT remains strict.
Please advise how to proceed!
You can verify your setup by confirming the connection details. Your PC uses a LAN cable for the internal network and also connects to the Wifi router via an external cable. The router model you mentioned is TL-WR840N.
I searched for ways to verify if my network uses double NAT. The guide suggested accessing your router’s settings and checking the WAN port’s IP address. If the IP falls within the private ranges like 10.x.x.x or 192.168.x.x, it indicates double NAT is likely in effect. My own setup doesn’t match those ranges, so it probably isn’t a double NAT scenario.
Usually Ethernet isn't the go-to for wide area network links, though I've heard some networks use small WAN segments with it. It's also possible, but ISPs sometimes route traffic through NAT64-CGN, which might lead to strict NAT scenarios. @Lurick What about an alternative? Also, the three typical private address blocks are 10.X.X.X, 172.16.X.X and 192.168.X.X. If none show up on your WAN port, it's likely you're not behind double NAT—unless you've configured one yourself.
In the case of CGNAT they employ this address space: 100.64.0.0/10
My public WAN IP isn't starting with that pattern either. It seems I'm not using double NAT. I've been working on this issue for over a day now.