I have a website, call it http://sub.example.com, hosted on, say, 72.xx.xx.x. There is a certificate for https://sub.example.com.

Now I go into the DNS management tool in my hosting provider, and I set up the standard subdomain forwarding wherein https://sub.example.com forwards to 72.xx.xx.x.

Now when I try to browse to https://sub.example.com, I get a certificate error saying it is for the wrong website.

I have also tried forwarding http://sub.example.com to 72.xx.xx.x, and tried it with domain masking in both cases. I am still getting the certificate error no matter what.

Additional wrinkle: if someone types in https://sub.example.com then the domain forwarding does not seem to work and IE just spins endlesssly and finally fails.

How can I domain forward the https://sub.example.com to 72.xx.xx.x?