If you wanna connect your Wii back to the internet but don't know how, change your DNS settings to 167.235.229.36 & 1.1.1.1. This'll let you use all the channels, mail, & wifi connections like RiiConnect24. Check wiilink24.com for more info.
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This can also work with your DS/3DS, if you connect 'em to a local hotspot or to the wifi before the servers shut down. To enable hotspot, disable data saver on your phone, enable hotspot, & connect your DS to it, with the same DNS settings.