I didn't see this thread at first, my apologies. Unknowingly posted this in the research thread.
Welp, having an issue. Using GTS Nuker, works perfectly from my PC to my DS when inputing the host PC as its local IP address. When I use the external IP address I've been unable to get it to work, both to my DS and my friends. It gets to nas.nintendowifi.net and just keeps looping there. Hard to explain in words, so I'll just attach an image:
Never gets past that, never attempts spoofing. Any ideas?