I have situations where we have web services deployed on customer sites and then encounter issues where clients fail to connect to them for reasons such as the port the service is running on has been blocked/not opened, certificate issues etc.

I’m try and trace the issues as in all cases these clients are app written by 3rd parties, I wanted to know if any logs or events would be created (these web services are running in IIS)? My theory is if the connection fails then there would be no log of the event as the request would not reach the server.

Any suggestions?