Calendar Overlay issue in SharePoint 2010

Question

I have a secured webapplication means that it uses "https" protocal, in which I have created two calendars Cal_1 and Cal_2. While trying to use the Calendar overlay option, it does not accept the "https" URL (Web URL:) however it recognize the "http" URL (Web URL:).

Is that a known issue with SharePoint 2010? If not, how it can be resolved?

Update:

1. From Client browser to Load Balancer it uses "https" protocal to communicate
2. From Load Balancer to WFE it uses "http" protocal to communicate

AAM Settings:
https://testapplication.test.com Default https://testapplication.test.com
http://testapplication.test.com Default https://testapplication.test.com

the microsoft KB - http://support.microsoft.com/kb/2025977 says that it should resolve the URL is in the default zone however in this case it does not.

so it seems that we should have a SSL binding for that webapplication in IIS level, is that true? or how it works?

Answer 1

The issue is that SharePoint isn't going to the calendar via the same path as the end user, meaning it doesn't go out to the load balancer on HTTPS and then back to the SharePoint server as HTTP.

Since you have HTTPS terminating at the load balancer, when SharePoint goes to access the HTTPS URL for the calendar, it is simply looping back to itself (no load balancer). The issue you are probably facing is that SharePoint is returning itself an SSL cert error since it's not where the HTTPS termination occurs.

So, in a nutshell, you would either need to terminate the SSL request on the IIS level or simply use the non-HTTPS version for your overlay. Since the server is talking to itself, using http for the overlay should be an issue.