Campus networks don't allow DS (NDS, NDSL, NDSi all inclusive) and Wii connections directly to their networks. You can register the devices with your campus and it *should* work, but I haven't tried that yet so no guarantees (woot for temporarily thwarting campus authorities!).
Buying your own wireless router would bypass this, but you'd need to set your encryption to Open or WEP (why they didn't fix this on the NDSi is beyond me). You have 2 other options though.
You can buy a used Nintendo DS WiFi Dongle from Gamestop here. (They lowered the price to $15. I bought it for $20 last year. Dammit.) Note that it is in-store only, and only in select stores. It will come with old software. Download the latest from Nintendo. It says that the software only works on WinXP. I run XP so I'm not sure if it has compatibility issues with Vista/7. Use the 'connect with USB connector' option on your DS.
You can buy any USB WiFi adapter that has SoftAP capabilities and create a virtual WEP/open network from your computer. Guide here. Use the 'connect to a wireless network' option on your DS. The official Nintendo WiFi dongle does the same thing with Nintendo's software and only allows Wii's and DS's to connect.
Buying your own wireless router would bypass this, but you'd need to set your encryption to Open or WEP (why they didn't fix this on the NDSi is beyond me). You have 2 other options though.
You can buy a used Nintendo DS WiFi Dongle from Gamestop here. (They lowered the price to $15. I bought it for $20 last year. Dammit.) Note that it is in-store only, and only in select stores. It will come with old software. Download the latest from Nintendo. It says that the software only works on WinXP. I run XP so I'm not sure if it has compatibility issues with Vista/7. Use the 'connect with USB connector' option on your DS.
You can buy any USB WiFi adapter that has SoftAP capabilities and create a virtual WEP/open network from your computer. Guide here. Use the 'connect to a wireless network' option on your DS. The official Nintendo WiFi dongle does the same thing with Nintendo's software and only allows Wii's and DS's to connect.