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.

[ifell]

i would to Feature Request an Addition of "Full Cone NAT" / "NAT Filtering: Open" Toggle

The Problem is
Currently, the Netduma R3 (DumaOS 4) lacks an explicit "NAT Filtering: Open/Secure" toggle. While the R3 supports PCP and UPnP, these protocols often result in a "Moderate" NAT type on PC for games with Peer-to-Peer (P2P) architectures, most notably Grand Theft Auto V.

Symmetric vs. Full Cone NAT: By default, the R3 appears to use "Restricted" or "Symmetric" NAT filtering. While this is secure, it is incompatible with many P2P matchmaking systems. Even when ports (like UDP 6672) are opened via PCP, the NAT remains "Moderate" because the router only allows incoming traffic from the specific IP/Port that the PC first contacted.

The "Full Cone" Requirement: For an "Open" NAT in GTA V, the router must support Full Cone NAT (Endpoint Independent Mapping). This allows any external host to send packets to the internal PC via the mapped port, regardless of whether the PC has messaged them first.

Regional Necessity (Australia/Oceania): For players in Australia, the player pool is smaller. A "Moderate" NAT limits the number of successful P2P handshakes, leading to much smaller or empty lobbies, "Timed Out" errors, and increased latency. when playing with some other friends i previously had no issues with, since i had a router that allowed me to set Nat filter to open.  An "Open" NAT is not just a label; it is a requirement for stable connectivity in isolated regions.

The Solution here is
I am requesting the addition of a "NAT Filtering" toggle in the WAN settings (similar to those found on Netgear, ASUS, and TP-Link hardware) that allows users to switch from "Secured" to "Open".

because DMZ is not an answer:
Using the DMZ is a "sledgehammer" approach that exposes the entire device to the internet. A "Full Cone NAT" or "Open Filtering" option provides the same connectivity benefits for gaming while maintaining a higher level of security by only affecting how active port mappings are handled.

so for goodness sakes add this feature, it would actually help MANY people out with the multitude of complaints about Nat type open and especially for an issue like one console having open Nat and the other 2 having moderate or strict

[Netduma Fraser]

I'll pass the request onto the team but I cannot guarantee if/when it may be implemented. Did you enable UPnP again along with your port forwards? It could be a misreading so have you actually tried to host and had issues with people connecting?

[ifell]

i've had lots of disconnects happen, and by comparison this didn't happen with i had a xr 1000 with nat filtering open, and my friends didn't disconnect or lag out, but with this R3... not having nat filtering open is seriously causing headaches after headaches, can't stress that enough

 

[Netduma Fraser]

Okay but if they can actually connect to you in the first place then it's nothing to do with NAT, otherwise they wouldn't be able to join you. The disconnects, is it you primarily disconnecting or them disconnecting from you? Can you provide the logs when it happens please? Did you also disable the Geo-Filter when you're hosting?

[ifell]

Well, my friends can’t always connect, and they don’t have the spare time to troubleshoot these issues with me. The only practical way to diagnose the problem is by asking what NAT type they have—one usually has Moderate, while the other sometimes gets Strict. They’re not tech-savvy, so there’s only so much they can realistically do on their end.

Because of these ongoing NAT-related issues, I end up having to reboot everything before even starting a gaming session. For example, when we play Call of Duty: Black Ops II, UPnP doesn’t provide an Open NAT, so I’m forced to manually forward UDP port 3074 just to make it work properly.

I’ve also tried manually forwarding the same style of ports for Grand Theft Auto Online, yet I still end up with Moderate NAT. This creates a major issue, especially for jobs or heists that already struggle with low player counts. It results in significantly longer wait times because I’m dealing with both a smaller pool of available players and the added restriction of Moderate NAT limiting who I can actually connect with.

I should also mention that I never use the Geo-Filter feature, so this isn’t being caused by any location-based filtering or connection restrictions on my side. These problems are happening under normal router usage.

Unfortunately, I can’t really provide logs at this point. I’ve already updated the Netduma R3 to the latest beta firmware and even factory reset it out of frustration, but the situation remains unchanged.

Since there’s no difference in Grand Theft Auto Online whether I use UPnP or manual port forwarding, I’ve now deleted all custom rules and gone back to letting UPnP handle everything. However, the game clearly seems to require Full Cone NAT to achieve an Open NAT type. I know this because when I previously used a NETGEAR Nighthawk XR1000 and had the same problems, enabling the Open NAT filter resolved everything immediately.

At this point, I really believe the Netduma team should seriously consider adding proper Full Cone NAT / NAT filtering options to the R3, because for gaming-focused hardware, these connection issues are causing far more trouble than they should.