When you’re working with Amazon and vRealize Automation Software Components, one of the requirements is for the Guest Agent (gugent) to talk back to the vRealize Automation APIs - the gugent polls the API for tasks it should perform, downloads them from the API and executes them, then updates the tasks with a status.
This means that Virtual Machines deployed as EC2 instances in an AWS VPC require the ability to talk back to internal corporate networks - not something you’d want to publish on the internet!