If you want to run ISPConfig behind a proxy, because you don't want to run SSL on port 81, but also don't want to change the ISPC code, you might want to run a proxy to redirect e.g. https://ispc.example.tld
You can setup an Apache configuration like for the ispc website (you can put this in the Apapche directives of an ISPconfig website if you like):
I did find some errors in the ISPC2 code unfortunately. Some parts of the code use a statement like:
to generate the URL. I believe this is wrong. You should leave it to the webserver to stick to its website. In order to solve this, I had to edit three files to make ISPC2 work correctly behind a proxy:
and remove the redirect link code per above for every entry which begins with
Perhaps this can be changed in the standard codebase of ISPConfig 2?