For the sake of security and safety, exercise environments where cyber operators train often need to be disconnected from real networks. To make these environments more realistic, the Software Engineering Institute (SEI) developed software that simulates the public Internet to give trainees the sense that they are in a real environment. In this SEI Cyber Talk episode, Rotem Guttman and Gabe Somlo explain how this software works to replicate common websites that users see on the Internet and make them as realistic as possible, which includes the addition of a DNS server infrastructure and making the websites appear as if they are hosted in different geographic locations. Rotem and Gabe also discuss how the software supports less common, but important, use cases like performing cryptocurrency transactions or running onion nodes.