This part of ISO/IEC 18028 provides detailed direction with respect to the security aspects of using Virtual Private Network (VPN) connections to inter-connect networks, and also to connect remote users to networks. It builds upon the network management direction provided in ISO/IEC 18028-1. It is aimed at those individuals responsible for the selection and implementation of the technical controls necessary to provide network security when using VPN connections, and for the subsequent network monitoring of VPN security thereafter. This part of ISO/IEC 18028 provides an overview of VPNs, presents VPN security objectives, and summarizes VPN security requirements. It gives guidance on the selection of secure VPNs, on the implementation of secure VPNs, and on the network monitoring of VPN security. It also provides information on typical technologies and protocols used by VPNs.