The evolution of the Internet of Things (IoT) and the vast amount of data that has been sent to the Cloud have pushed the horizon to Fog computing paradigm. Thus, Cloud processing is migrating to the edge of the network. As a consequence, Fog-to-Fog communications are becoming one of the main concerns regarding IoT security. Recent works have presented the CoAP protocol as a secure approach for Fog devices communications. CoAP’s security is based on DTLS and has adjustments to support unreliability issues on UDP communications. However, the DTLS protocol was not designed to be used in Fog-to-Fog communications. Although some research efforts have worked on DTLS optimizations, none of them has analyzed its suitability in the Fog computing perspective, which involves time-critical applications and radio access networks (RANs). Thus, this paper evaluates the DTLS protocol from CoAP in Fog-to-Fog communications analyzing performance, overhead, and handshake issues when operating in RANs. Tests revealed that DTLS from CoAP is suitable for Fog-to-Fog communications using HSPA+ and LTE as radio access networks.