Cannot connect to the internet on my iPhone 4S after upgrading to iOS 5.1 Just updated the iOS to 5.1 this morning and now I cannot connect to the internet. WiFi is not available to me right now...
You will need to re-enter the network settings. Updating iOS seems to wipe these settings.

Go to Settings → General → Network → Cellular Data Network and enter all fields.



To use a VPN connection, Choose Settings → General → Network → VPN and then choose “Add VPN Configuration”. Ask your company’s IT guy for the credentials.