For your CA and NDES service to be accessible and used by Intune, you must install Azure Active Directory Proxy on both the CA server and the NDES server.
To manage devices behind firewalls and proxy servers, you must enable communication for Intune. The proxy server must support HTTP (80) and HTTPS (443).
The directory proxy can be used to proxy LDAP requests to multiple back-end directory servers. Location: The proxy image is hosted in an IBM Cloud Repository, ...