For more information about the Online Certificate Status Protocol (OCSP) and the benefits of OCSP stapling, see Enable OCSP Stapling on Your Server.
Check if OCSP stapling is enabled.
With Windows servers, all you need to do is verify what version of Windows Server you are running.
Windows Server 2008+ - OCSP stapling is enabled
OCSP stapling is supported and enabled by default in Windows Server 2008 and later.
Windows Server pre-2008 - OCSP stapling is not enabled
OCSP stapling is not supported/ included as a feature in Windows Server pre-2008.
Upgrade to Windows Server 2008+.
If you are running Windows Server pre-2008, to enable OCSP stapling, upgrade to Windows Server 2008 or later.
Check the Windows server connection to the OCSP server.
Open a browser and go to ocsp.digicert.com/ping.html. You should receive the “You have successfully reached the DigiCert OCSP Service” message.
If you are unable to connect to the OCSP server, it is most likely a network or firewall problem.