Lag and NAT issues in Dune 2000 multiplayer on modern network hardware?

[caroljames97202]

Hey everyone, long-time lurker here. I’ve recently been on a massive Westwood RTS kick and decided to dust off Dune 2000 for some multiplayer action via CNCNet. It’s been great reliving those Harkonnen campaigns, but I’ve hit a technical wall that’s honestly driving me a bit crazy and I'm hoping someone here has dealt with something similar.
The specific point I’m struggling with is the frequent "Unable to connect to players" error, especially when I try to host a lobby. I’ve noticed this started happening right after I upgraded my home setup to a newer wireless gateway provided by my ISP. While the raw speeds are incredible for downloading huge modern titles, I have a feeling the way this gateway handles NAT and internal traffic is totally clashing with the peer-to-peer protocols that older games like Dune 2000 rely on.
I remember back in the late 90s, the biggest hurdle was just getting a stable phone line without someone picking up the extension. Now, I have fiber-level speeds, but the "smart" security features on this modern gateway seem to flag classic game traffic as suspicious. I’ve gone into the admin panel to mess with port forwarding and even tried toggling the UPnP settings, but I’m still seeing these weird latency spikes every time a large group of units starts moving on screen. It’s like the hardware is trying too hard to "optimize" the packet flow and ends up causing a bottleneck for the real-time data these older engines need.
Has anyone else here successfully navigated the settings on a modern wireless gateway to keep their retro RTS matches stable, or are we just doomed to deal with these "smart" security layers getting in the way of our nostalgia? I’d hate to give up on multiplayer just because my hardware is too clever for its own good.