Do both Sandbox and Test environments support my company's public and private IP addresses?
Private IPs are internal to your organization and are not exposed to external services. They are routed through a public IP, This is similar to the router or modem that you have at your house. If you have multiple PCs or other devices connected to the router, each device has a private IP. But for the outside (web pages, services, etc) it only exposes the public IP from the router.