No, despair no more, because I have come up with the perfect solution on how you can let your DSi (and its alikes) go online, playing with other people, AND keep a highly secured internet (such as WPA, WPA2 or both put together).
For those unfamiliar with what I’m talking about, let me tell you what the main problem here is. The problem is that Nintendo has for some reason only allowed their handheld game devices in the series of Nintendo DS, only hook up to an open or WEP-secured router. With the DSi, they did allow you to connect to a WPA-secured one as well, but not for gaming, only for usage of the web browser and such activities. The thing is, most people enjoy playing against other people or together with other people. Interaction is fun, or at least fun to be accessible. But as I have indirectly pointed out: WEP is a much weaker security system than all the other options (except open, of course). Therefore, most people will not set the security to this setting, and so Nintendo is losing tons of potential online gamers.
Until today. Because after having looked for another problem with my router yesterday, I figured out how to solve the problem. And it’s so simple, many people out there will now think “Why didn’t I think of THAT?!”.
This is what you need to do: Make an isolated guest network with WEP settings. And that’s it! Since it’s isolated, it won’t allow anyone to access your main options from it, they have to be connected to your main SSID and go from there. And your main SSID is of course then secured as highly as possible.
I’m not sure if this works for all routers, but it certainly does with Netgear. So I hope this helped someone else as well out of a pickle, because it sure helped me.