Staging Applications using url rewrite

web.config

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <rewrite>
            <rules>
                <!-- Stage A:
                         A(enabled) B(enabled,negate)
	                 
                     Stage B:
	                     A(enabled,negate) B(enabled)
	                 
                     Production A:
	                     A(enabled,negate) B(enabled)
	                 
                     Production B:
	                     A(enabled) B(enabled,negate)
	                 
                     Live A:
	                     A(enabled,comment) B(disabled)
                     
                     Live B:
	                     A(disabled) B(enabled,comment) -->

                <remove name="Use A" />
                <remove name="Use B" />
                <rule name="Use A" stopProcessing="true">
                    <conditions>
                        <!--<add input="{Authorized Admin IPs:{REMOTE_ADDR}}" pattern="1" negate="true"/>-->
                    </conditions>
                    <match url="^(.*)$" ignoreCase="true" />
                    <action type="Rewrite" url="a/{R:1}" />
                </rule>
                <rule name="Use B" stopProcessing="true" enabled="false" >
                    <conditions>
                        <add input="{Authorized Admin IPs:{REMOTE_ADDR}}" pattern="1" />
                    </conditions>
                    <match url="^(.*)$" ignoreCase="true" />
                    <action type="Rewrite" url="b/{R:1}" />
                </rule>
            </rules>
            <rewriteMaps>
                <rewriteMap name="Authorized Admin IPs">
                    <add key="110.34.4.242" value="1" />
                </rewriteMap>
            </rewriteMaps>
        </rewrite>
        <directoryBrowse enabled="false" />
    </system.webServer>
</configuration>