log4net.md

If you aren't seeing log messages, try adding this to your web.config:

<appSettings>
  <add key="log4net.Internal.Debug" value="true"/>
</appSettings>
...
<system.diagnostics>
  <trace autoflush="true">
    <listeners>
      <add 
          name="textWriterTraceListener" 
          type="System.Diagnostics.TextWriterTraceListener" 
          initializeData="C:\temp\log4net.txt" />
    </listeners>
  </trace>
</system.diagnostics>

(from https://stackoverflow.com/questions/3121975/log4net-appenders-not-working-in-iis7-5)