IE11 unable to connect to local IIS, other browsers work fine

Question

I\'m using the XIP.IO wildcard domain to access a website running on a local IIS server.

Today, IE 11 stopped accessing the site, whilst Chrome and Firefox continued to

Answer 1

Internet Explorer 11 includes a new isolation technology called AppContainer which is used by the Enhanced Protected Mode feature of the browser. EPM/AppContainer network restrictions help mitigate attacks against the computer by preventing content in the Internet Zone from connecting to your local network or your local PC.

The problem you're encountering occurs when the zone settings are such that your Local PC's content is treated as Internet Zone. If you were to use the machine name (e.g. http://mypc or http://localhost) the content would load in the Intranet Zone and thus outside of Protected Mode and thus outside of the AppContainer.

The same feature prevents IE11 from using Fiddler in your scenario; you can learn more about this issue here: http://fiddler2.com/blog/blog/2013/08/02/fiddler-and-internet-explorer-11-on-windows-8-1

To resolve this issue, use the Win8 Config tool at the left of Fiddler's toolbar (or download the standalone EnableLoopback tool from http://blogs.msdn.com/b/fiddler/archive/2011/12/10/fiddler-windows-8-apps-enable-loopback-network-isolation-exemption.aspx)