Taken directly from: https://developer.apple.com/library/mac/qa/qa1176/_index.html#//apple_ref/doc/uid/DTS10001707-CH1-SECRVI
iOS 5 added a remote virtual interface (RVI) facility that lets you use OS X packet trace programs to capture traces from an iOS device. The basic strategy is:
- Connect your iOS device to your Mac via USB.
- Set up an RVI for that device. This creates a virtual network interface on your Mac that represents the iOS device's networking stack.
- Run your OS X packet trace program, and point it at the RVI created in the previous step.
- To set up an RVI, you should run the rvictl tool as shown below.