How set default page in iis for Asp.net application

There are two ways to be set default page for application.One way is adding the default document to configuration file(web.config).Other way is directly set the default document in IIS

<system.webServer>
    <defaultDocument>
        <files>
            <add value="~/OrdsrHome.aspx"/>
        </files>
    </defaultDocument>
</system.webServer>

Configure in IIS :
Click on application -->go to Features view then do the below process as per screen shots

The default Page has been set to application as you can see in the above image