Android Emulator loopback to IIS Express does not work, but does work with Cassini

I am attempting to post data from an Android application running in the Android Emulator on my local machine to a web application running under IIS Express also running on my local machine. Unfortunately, when I post to 10.0.2.2 from the emulator I receive a Host Not Found error message.

If I configure the web application to run under ASP.NET Dev Server (Cassini) instead of IIS Express the Android application is able to post with no problems. What configuration am I missing for IIS Express that is preventing it from working with a loopback from the Android emulator?


Grant yourself permission to bind to network adapters other than localhost, and configure IIS express to bind to all adapters.

IIS Express will then accept connections from the Android emulator via 10.0.2.2. If you add a rule to the firewall, you can also expose IIS Express to your network, which decreases security but is useful for testing physical devices.

Step details: (they assume a port number of 5555 - use your actual port instead)

  1. Run this from a command prompt as Administrator:

    netsh http add urlacl url=http://*:5555/ user="NT AUTHORITY\INTERACTIVE"

  2. In %USERPROFILE%\Documents\IISExpress\config\applicationhost.config, replace your site's localhost binding with bindingInformation="*:5555:*". The result should look like this:

    <site name="..." id="...">
        <!-- application settings omitted for brevity -->
        <bindings>
            <binding protocol="http" bindingInformation="*:5555:*" />
        </bindings>
    </site>

Add following line to IIs config file (ex c:\Users[YourName]\Documents\IISExpress\config\applicationhost.config ) Change the port 8085 if required..

<binding protocol="http" bindingInformation="*:8085:127.0.0.1" />

so your config file will end-up with something like this

<bindings>
<binding protocol="http" bindingInformation="*:4396:localhost" />     // the existing one
<binding protocol="http" bindingInformation="*:8085:127.0.0.1" />     // new line
</bindings>

now you can call your web service from remote by calling to port 8085

ex from android emu.
new HttpPost("http://10.0.2.2:8085");

By default, IIS Express only accepts connections from localhost. To enable connections from remote devices (and the emulator counts as such), use the instructions from here.

In short:

netsh http add urlacl url=http://[machinename]:[port]/ user=everyone
netsh http delete urlacl url=http://[machinename]:[port]/

Replace [machinename] and [port] with your computer name (or non-local IP) and port IIS Express runs on.

Also, see this question and this one.