Simulated environments can provide a convenient, effective way to teach skills. Simulations have been used for decades to teach skills such as piloting aircraft. As technology has improved, it has become feasible to simulate many other tasks. Recent advances in virtual and augmented reality provide new avenues for expanding training using simulations. Going forward, it is imperative that we understand how skills are transferred from simulated environments to physical environments. The current research investigated network simulation training in an introductory computer networking course. Students completed networking exercises in a simulated network environment using Cisco Packet Tracer then subsequently completed exercises using physical Cisco routers and switches. Data from the study indicates that simulations are effective tools to teach computer networking principles but may not necessarily eliminate the need for students to learn using physical networking equipment. Student perceptions of simulation realism explained a large portion of the variance in skill transference between the simulated and physical environments. Practical advice for instructors teaching networking using simulated and physical environments is given.