Instructions on how to setup most devices for Stanford's VPN is available on the University IT website at: vpn.stanford.edu. The easiest way to set this up on your iOS device is to install Mobile Device Manager ("MDM"). However, students are not required to install MDM on their personal devices. You can also set up VPN yourself with the instructions below:
Setting up VPN:
Go to Settings > General > VPN > Add VPN Configuration.
Under “Type”, the default is IKEv2 but you want to change it to IPSec...
Description = whatever you want to call it.
Server = su-vpn.stanford.edu
Account = your SUnetID
Password = leave this blank
Certificate = don’t need it.
Group Name = FullTraffic (note there’s no space between Full and Traffic. Also, capitalization matters)
Secret = Stanford (capitalization matters here too).
Connecting via VPN:
Settings > toggle VPN to the ON position
A pop up will appear with your SUnetID already on it. You’ll need to enter your password.
Another pop up will appear asking for you two-step authentication.
Related: How do I setup VPN on my device?