Sniffing 3G Data

I always assumed there was some sneaky way to watch the network traffic from my iPhone over a 3G network but I never gave it a shot until today. As it turns out, it’s pretty easy.

I used a VPN connection to make this work. I don’t know of a way to setup a proxy just for your 3G connection but if there is a way then any computer with a public IP Address would work.

I used Fiddler to watch the traffic but any network monitor will work. Here’s a good tutorial on setting up Fiddler. IMPORTANT: You only need to do steps 1 and 2 in this tutorial and then make sure to RESTART FIDDLER!

1. Connect your iPhone to a VPN (iOS: Setting up VPN)
2. On your iPhone, go to Settings | General | Network | VPN and click the blue arrow next to the VPN connection you are using.
3. Now you should be on a screen titled “Add Configuration”. Scroll to the bottom and in the “Proxy” section select “Manual”.
4. For the Server, enter the IP Address of the computer you wish to send the data through (ie. 10.2.1.100).
5. For the Port, use 8888 (assuming you’ve done the Fiddler tutorial listed above)
6. Authentication, in my case, is set to Off.
7. Save those settings and open Safari or any app and start sniffing!