This simple IIS rewrite rule should send requests to another http-server application on the same machine but it does not. Any idea why?
<configuration>
<system.webServer>
<rewrite>
<rules>
<rule name="MyRule">
<match url="/app/(.*)" />
<action type="Rewrite" url="http://localhost:88/app/{R:1}" logRewrittenUrl="true" />
</rule>
</rules>
</rewrite>
</system.webServer>
</configuration>
URLs like http://server.domain.com/something should go to IIS running on port 80. URLs like http://server.domain.com/app/something should be sent to an application running on port 88 but the log says "POST /app/something HTTP/1.1" 404