Cannot profile IIS 6 web application on port lower than 1024

Category: Troubleshooting & error messages
Date: 20 May 2009
Product: ANTS Profiler
Versions: ANTS Performance Profiler 4.0
Fix Version: This issue has been fixed in version 4.1

When profiling a web application hosted in IIS, ANTS Profiler's "profile on an unused port" spinbox allows you to choose any TCP port in the range 1-65535. If the port selected is lower than 1024, however, ANTS Profiler ignores the setting and uses TCP port 8013. When profiling the web application hosted in the development web server, the port is automatically changed to 1024 whenever the spinbox loses focus.

If you have web applications that are hard-coded to use a TCP port lower than 1024 and you must use IIS version 6 as a platform to run the web application, the workaround is to use IIS 5 isolation mode.

  - Open IIS Manager
  - Expand the server icon
  - Right-click the "Web Sites" folder and select "Properties"
  - Click the Service tab
  - Click the checkbox marked "Run WWW service in IIS 5.0 isolation mode"

When you are finished profiling, you may go through the same steps to de-select the isolation mode checkbox and your application pools and configuration will remain intact.

Note that IIS 5 and IIS 7 are not impacted by this issue, provided that on IIS 7, the "profile on an unused port" option is not used.

There is no current workaround for the development webserver; the application must be hosted in IIS when profiled if it's necessary for the web application to be bound to a port numbered 1023 or lower.

This behavior does not occur in ANTS Profiler version 4.1 and higher.