Sometimes the Internet Data Sharing feature will work fine from a home internet connection, or over a cell phone’s network connection, but will fail when the host device is on a school network. This most often happens when the school network is blocking a port or site needed by Data Sharing.

Data sharing uses ports 443, 3478, and sometimes 5004. It also requires a transient connection to the site If the site or ports are blocked, Data Sharing may fail.

It is also possible that Data Sharing will fail if a network blocks web access with a captive portal authentication model.