This episode focuses on logical infrastructure security as the layer that prevents broad compromise when credentials leak or an attacker gains a foothold, which is commonly tested through DS0-001-style scenarios involving unintended exposure or lateral movement. You’ll review network controls like security groups, firewalls, and routing policies, then connect them to perimeter concepts and why “perimeter-only” thinking fails in modern environments. Segmentation will be framed as limiting blast radius by isolating database tiers, management planes, and replication traffic, and by enforcing strict source and destination rules rather than relying on trust inside a network. Hardening will include reducing exposed services, disabling legacy protocols, enforcing secure configuration baselines, and ensuring management access is constrained through controlled jump points and strong authentication. You’ll practice troubleshooting prompts where a database is reachable from the wrong subnet, where replication fails because only one direction is permitted, or where a “simple” hardening change breaks clients due to TLS settings or certificate trust. By the end, you should be able to propose security improvements that preserve required functionality while measurably reducing attack surface and making incident containment more realistic. Produced by BareMetalCyber.com, where you’ll find more cyber audio courses, books, and information to strengthen your educational path. Also, if you want to stay up to date with the latest news, visit DailyCyber.News for a newsletter you can use, and a daily podcast you can commute with.