I would like to restrict the acces to the Pulse VPN to Iphone only, hence I want to block connection coming from PC, Linux, mac.....
Is there a way to say: If remote_user = PC then deny connection
If and only if remote_user = iphone then connection is allowed
This is possible by using host checker restriction via user agent string or running an OS Check for iOS. My recommendation would be running an OS Check for iOS to ensure all endpoints are running the latest OS version before they are allowed access to the PCS device.
In addition to Host Checker, you can alternately do a browser agent restriction and configure it for *iPhone*Pulse* on the realm