Knowledge of Local Area Networks (LAN), Wide Area Networks (WAN), Wireless Local Area Networks (WLAN), Virtual Private Networks (VPN), Transmission Control Protocol/Internet Protocol (TCP/IP), Dynamic Host Configuration Protocol (DHCP), Domain Name System (DNS), directory services, and the Open Systems Interconnection (OSI) model. Personnel Certification: Applicable certifications include Certified Ethical Hacker (CEH), CompTIA Cloud+, GIAC Certified Incident Handler (GCIH), Global Industrial Cyber Security Professional (GICSP), GIAC Security Essentials (GSEC), CompTIA Security+, and Systems Security Certified Practitioner (SSCP).