Earn Continuing Professional Education (CPE) credits at no cost and receive a certificate upon completion.
Defense in Depth is a practical approach to reducing risk by layering controls to prevent, detect, and contain cyber threats. This free course explains how to build resilient network defenses using segmentation, DNS security, network analytics, Zero Trust Network Access (ZTNA), VPNs, and strong authentication and logging practices.
Start the course now and complete the training at your own pace.
Module 1 introduces the course goals and explains why defense in depth is still one of the most effective ways to manage cyber risk. It frames secure network design as a set of practical decisions that reduce exposure, limit blast radius, and improve detection.
Module 2 introduces the concept of Defense in Depth as a foundational cybersecurity design principle. It explains why relying on single controls is insufficient and how layered defenses reduce the likelihood and impact of compromise. This module establishes Defense in Depth as a mindset that informs architecture, not a checklist of tools.
Module 3 focuses on DNS security as a critical but often overlooked layer in a Defense in Depth strategy. It explains how DNS is used by attackers for command-and-control, data exfiltration, and evasion, and how defenders can leverage DNS controls for visibility and disruption. This module highlights DNS as both an attack surface and a defensive opportunity.
Module 4 examines network segmentation and its role in limiting attacker movement and reducing blast radius. It explains different segmentation approaches, common implementation challenges, and why segmentation decisions must balance security, operations, and complexity. This module reinforces segmentation as a practical risk-reduction control rather than a purely theoretical design.
This module explores network analytics as a core component of effective Defense in Depth. It explains how visibility into network traffic supports detection, investigation, and response, and why architectures must be designed for monitoring and security—not just connectivity.
Module 6 introduces Zero Trust Network Access (ZTNA) and explains how it fits within a Defense in Depth approach. It clarifies common misconceptions about Zero Trust and highlights the importance of identity, authentication, and access control in modern network design. This module positions ZTNA as an architectural strategy, not a single product or solution.
Module 7 examines the role of Virtual Private Networks (VPNs) within a layered security architecture. It discusses common misconceptions about VPN security, appropriate use cases, and limitations when used alone. This module helps learners understand where VPNs fit—and where they fall short—within a Defense in Depth strategy.
This course explains Defense in Depth as a practical design approach for building resilient security programs and networks. It focuses on how layered controls work together, why single-point solutions fail, and how to strengthen visibility, access control, and containment in real-world environments.
Key topics covered include:
How Defense in Depth fundamentals and layered security reduce risk more effectively than relying on a single control
How to select and align defensive layers across identity, network design, monitoring, and response—without turning security into unnecessary complexity
DNS security as both an attack surface and a defensive control, including how attackers use DNS and how defenders can use it for visibility and disruption
Network segmentation concepts and implementation considerations that limit lateral movement and reduce blast radius
Network visibility and analytics—how telemetry, logging, and traffic analysis support detection, investigation, and incident response
Zero Trust Network Access (ZTNA) fundamentals and how identity-driven access decisions fit into a broader Defense in Depth approach
The role of VPNs in modern environments, including appropriate use cases, common misconceptions, and limitations when used as a standalone control
Meet Your Instructor
MS, CAWFE, CEH, CFCE, CHFI, CISSP, CNDA, DFCP, GCFA, GCFR, GCIA, GIME, GSEC
Josh Moulin is a cybersecurity leader with over 20 years of experience protecting critical systems and advising organizations across government and industry. His background includes leading cyber operations and incident response efforts, building security programs, and supporting high-consequence environments where secure network design, visibility, and access control directly impact mission outcomes.
Josh began his career in law enforcement, where he led a cybercrimes task force and a digital forensics lab, and later served as a CIO and CISO within the U.S. nuclear weapons complex. He also held senior leadership roles at the Center for Internet Security (CIS) supporting nationwide security operations, and served as an Executive Partner at Gartner advising large, complex organizations on cybersecurity strategy and risk.
In addition to leading Natsar, Josh is adjunct faculty teaching university courses in cybersecurity and digital forensics. His training is built to be practical, clear, and immediately usable—focused on helping professionals apply proven security concepts in real-world environments.
You've got questions. We've got answers.
Yes. This is a no-cost course designed to provide practical training and help you earn Continuing Professional Education (CPE) credits.
Yes. After you complete the course, you’ll receive a completion certificate you can retain as documentation for CPE submission.
Yes. Natsar delivers customized training for individuals and organizations across a wide range of cybersecurity and digital forensics topics. If you’re interested, contact us at [email protected].