R3 DumaOS 4 - Achieving Open NAT for P2P Hosting (GTA Online)

[ifell]

I am trying to achieve an Open NAT in GTA Online (PC) to host lobbies for achievements. Despite a perfect setup, the game consistently reports Moderate NAT.
 

 Netduma R3 Firmware: v4.0.540

Connection: Direct NBN Fiber (FTTP) to NTD (No ISP modem/Bridge mode issues)
Ports: All Rockstar-required ports (6672, 61455-61458 UDP, etc.) are manually forwarded. UPnP is disabled to avoid conflicts.

I cannot find a toggle for 'NAT Filtering: Open' or 'Endpoint Independent Mapping' in the DumaOS 4 interface. It appears the R3 is performing Symmetric or Address-Restricted NAT by default, which is preventing me from being the primary session host.

[Netduma Fraser]

You can enable UPnP, although you're correct it would avoid conflicts by keeping it disabled its quite unlikely to happen and I've never seen it cause any issues with both enabled and it may help you in this scenario. With that and the required ports it's unlikely you would actually have a moderate NAT even if its reporting it - have you actually hosted and had issues with people joining to check if it is moderate? If people can join then you will be open.

Short of putting the PC in the DMZ which is a security no-go there aren't any other settings you could adjust to get an Open NAT. Do make sure to disable the Geo-Filter though as that could cause issues with people joining.