After upgrading to .NET Framework 3.5, I can't set 80 as a HTTPS port in IIS6. Only when I uninstalled .NET Framework 3.5, IIS accepts 80 as a HTTPS port again and operate normally.
The question is whether this behaviour is by design or a bug results from unexpected interaction between IIS and .NET Framework 3.5.
To my understanding, Dot Net Framework should be web server agnostic and IIS should be software framework agnostic. Thus, if this behavior is indeed a design choice, why it did not show up in early versions of Dot Net Framework, e,g. 1.1 2.0？
Reproduction Steps： 1. Set 80 as a HTTPS port in IIS6
Install .Net framework 3.5
run "inetmgr", it appears that website is stopped.
Remove port 80 from https configuration or uninstall framework 3.5, website is able to start again