WGU D315 Network and Security Foundations | PA & OA Verified Exam Prep 2025/2026 | 200+ Q&A | OSI & TCP/IP Models, Cloud, & Cyber Security

Pass your WGU D315 Network and Security Foundations course on the first attempt with this comprehensive, verified study guide. Updated for the 2025/2026 academic year, this resource covers every critical competency required for both the Pre-Assessment (PA) and the Objective Assessment (OA). With over 200 high-yield questions and detailed answers, you will master the foundational concepts of modern networking and information security. This guide features an in-depth breakdown of the OSI 7-Layer Model and its mapping to the TCP/IP stack, ensuring you can distinguish between protocols like HTTP, TCP/UDP, and IP at every level. You will gain a clear understanding of hardware devices, including Routers, Switches, Hubs, and Modems, and how they operate across different network topologies. Security is a major focus of this document. It includes detailed sections on the CIA Triad (Confidentiality, Integrity, Availability), Cloud Computing Models (IaaS, PaaS, SaaS), and Virtualization (Type 1 vs Type 2 Hypervisors). Prepare for the "Security" half of the OA with verified Q&A on common attacks such as SQL Injection, Man-in-the-Middle, ARP Poisoning, and Social Engineering. Additionally, the guide covers essential command-line tools for troubleshooting, including Ping, Traceroute, Ipconfig, and Nslookup. Whether you are new to IT or looking for a final review, this document is the ultimate cheat sheet to help you navigate the D315 roadblock and move toward your WGU degree.