No iPhone traffic captured after Windows connects to VPN

[Nate]

I have Fiddler v5 set up on Windows 10. I have followed the instructions for capturing iOS traffic detailed here, http://docs.telerik.com/fiddler/configure-fiddler/tasks/ConfigureForiOS

When Windows is not on a VPN, I can capture the traffic from my iPhone 8 with iOS 12.1 via Manual proxy setting and port 8888. However, when I connect to a VPN (Pulse Secure Network Connect 8.3) and then start up Fiddler, running as Administrator, I can then no longer load web pages in Safari on my iPhone and Fiddler doesn't capture any iOS traffic.

On the Tools > Options > Connections settings, I do have "Monitor all connections" checked.

What could prevent the proxy from working while on the VPN?

Thanks,

Nate

[Simeon]

Hi Nate,

Please, note that how exactly the Pulse Secure Network Connect 8.3 works, is out of my scope. With this said, let me answer your question with my best assumption:
 What could prevent the proxy from working while on the VPN? 

Usually, when you connect to a virtual private network, all your network data are transferred through the VPN connection to the remote network. In simple words, you are "moving" (virtually) your computer from your local network into the remote network through the VPN connection.

However, your phone is still connected to the local network. Now your phone and your computer are in two different networks. I believe that there is no routing (visibility) between the two networks and there is no way for your phone to communicate with your computer.

I hope that this answers your question.

Regards,
Simeon
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