The buzzword at the 2017 RSA Conference was “Software Defined Perimeter.” At least two dozen prominent booths had painted the phrase on the booth or dropped the phrase in the first 30 seconds of conversation. What is a Software Defined Perimeter (SDP)? How does it differ from a Software Defined Network (SDN)? Software Defined Networks started as ways to improve the efficiency of datacenter networking by leveraging automation and open frameworks to improve on legacy networking hardware stacks used by many. These have proven very successful. In the frenzy to adopt cloud that has marked the last 10 years of IT, a key network component has been forgotten. Now generally referred to as the Edge, it is the portion of the network that operates on premise. Traditionally protected by a next gen firewall, the Edge presents opportunities to some of the more difficult problems created by the cloud transition. Software Defined Perimeters extend the benefits of SDN into the Edge. SDP can replace traditional firewalls or overlay legacy hardware for new security features, machine learning, high bandwidth applications like anomaly detection, and more. These benefits are catalyzed by the low total cost of owners and ease of management a SDP provides over hardware based systems.