Secure information networks and connected applications from unauthorized use. Consider information classification, device management procedures, network documentation, separating network and ICT system activities, safeguarding data confidentiality, monitoring, logging, coordinating network administration, authenticating systems, restricting and reviewing connections, detecting and authenticating device connections, hardening network devices, segregating administration channels, momentarily isolating critical subnetworks, and disabling vulnerable protocols. Ensure virtualized networks have needed security measures, including software-specified networking.