To monitor network traffic from a Mac using Fiddler on a virtual machine, start Fiddler, enable remote connections, and restart it. Note the virtual machine's IP address. On the Mac, enable the web proxy options and point them to that IP address on port 8888. Download and install Fiddler's certificate to decrypt secure HTTPS traffic between the Mac and virtual machine.

1. Start the Virtual Machine and install Fiddler.
Start Fiddler and click Tools > Fiddler Options > Connections. Tick the ¡°Allow
remote computers to connect¡± box.
Restart Fiddler.
Note the IPv4 address of the Fiddler instance by hovering over the Online icon
in Fiddler¡¯s toolbar, or run ifconfig eth0 in the terminal (Linux) or ipconfig
(Windows).
On the Mac, click the Apple Menu > System Preferences > Network.
Click the Advanced button.
On the Proxies tab, Enable the Web Proxy (HTTP) and Secure Web Proxy (HTTPS)
options to point to the IPv4 address of the virtual machine (found in Step #7)
using port 8888.
To decrypt HTTPS traffic, you¡¯ll need to install the HTTPS certificate in the
Mac¡¯s keychain. You can download this certificate by visiting the
http://IPAddress:8888.