While setting up Visual Studio Team System (VSTS) virtual machines (VM) for our demos or customization projects one of our requirements is to be able to run the VM while not connected to a physical network. We therefore have a tendency to use the Microsoft Loopback Adapter as one of the network adapters and configure Internet Connection Sharing to provide Internet access when connected to a network.
I personally use a third party firewall so I have a tendency to disable the built in Windows Firewall. So, when I tried to configure Internet Connection Sharing I get the following error:
"An error occurred when enabling internet connection sharing. (null)"
After some searching that resulted in many posts on how to configure but none specifically on my error, I came across a response in a message on one of the forums somewhere (exactly where it escapes me). It turns out that to get around this error and be able to configure Internet Connection Sharing the Windows Firewall must be enabled. So, I simply enabled the Window Firewall service just before the configuration process and disable it thereafter. Problem solved.
