Can't access WEB API with ip:port but can with localhost:port during VS debug mode

If you're running it in debug mode I assume you're using IIS-Express.

By default, IIS-Express only binds to localhost.

To circumvent this, you can open the IIS-Express application config file located at: C:\Users\<username>\My Documents\IISExpress\config\applicationhost.config and modify the site's binding information.

change

<binding protocol="http" bindingInformation="*:55284:localhost" />

to

<binding protocol="http" bindingInformation="*:55284:*" />

You'll also have to restart IIS-Express after the change.

Both Anton and Matthew's Answers pointed me to the right direction

So this what I did

1. Run Visual Studios in administrator mode

2. Changed the binding protocols and allow for incoming directions as suggested http://johan.driessen.se/posts/Accessing-an-IIS-Express-site-from-a-remote-computer

   But after that, I have a service unavailable (503) error

3. So I followed this : IIS Express Enable External Request - 503 Added just the port protocol and port:ip protocol,

Than it works both on my machine's browser and on my phone.

Not too too sure why the 3rd step is needed -my hypothesis is (the localhost url is needed for VS to point to and the ip url is used for accessing from another machine)

I had the same problems when I wanted to share my localhost IIS so some guys could just type my machine name or IP and connect to my web app instance. So if this is what you need when http://johan.driessen.se/posts/Accessing-an-IIS-Express-site-from-a-remote-computer. It works for me for both Silverlight and MVC apps. I even set breakpoints and they are hit from a remote machine.