We can enable tracing for the entire application by adding tracing settings in web.config. In code Listing 2, pageOutput="false" and requestLimit="25" are used. This means trace information is stored for 25 requests, but not displayed on the page because pageOutput attribute is set to false.

Listing 2

<configuration>
    <appSettings/>
    <connectionStrings/>
    <system.web>
        <compilation debug="false" />
        <authentication mode="Windows" />
      <trace enabled ="true" pageOutput ="false" requestLimit ="25" 
          traceMode ="SortByTime " />        
    </system.web>
</configuration>

The page-level settings take precedence over settings in Web.config, so if enabled="false" is set in Web.config but trace="true" is set on the page, tracing will occur.