<log4net>
    <logger name="logger">
      <!--Loggers may be assigned levels. Levels are instances of the log4net.Core.Level  class. The following levels are defined in order of increasing priority:

      * ALL
      * DEBUG
      * INFO
      * WARN
      * ERROR
      * FATAL
      * OFF-->

      <level value="ERROR"/>
      <appender-ref ref="RollingLogFileAppender" />
      <appender-ref ref="TraceAppender" />
    </logger>

    <appender name="TraceAppender" type="log4net.Appender.TraceAppender">
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
      </layout>
    </appender>

    <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender,log4net">
      <param name="File" value="diagnostics.log" />
      <param name="AppendToFile" value="true" />
      <param name="MaxSizeRollBackups" value="10" />
      <param name="MaximumFileSize" value="5MB" />
      <param name="RollingStyle" value="Size" />
      <param name="StaticLogFileName" value="true" />

      <layout type="log4net.Layout.PatternLayout,log4net">
        <header value="******************************************************&#xD;&#xA;********************* START **************************&#xD;&#xA;******************************************************&#xD;&#xA;" />
        <footer value="*********************** END **************************&#xD;&#xA;&#xD;&#xA;" />
        <param name="ConversionPattern" value="%d [%t] %-5p %c [%x] - %m%n" />
      </layout>
    </appender>
  </log4net>

Log4Net web.config

xml

XML