What is the recommended method to secure communication between Portal for ArcGIS and ArcGIS Server in a federated site?

A government agency needs to design an ArcGIS Enterprise architecture where ArcGIS Server and Portal communicate securely without exposing internal hostnames. What should the architect configure?

Which factor influences whether an organization uses tiered or flat architecture?

Which ArcGIS Enterprise component typically consumes the most disk I/O in large map-service deployments?

Which type of machine sizing metric should be prioritized when deploying a spatiotemporal big data store?