This podcast offer a comprehensive examination of the Internet Protocol Security (IPsec) suite, detailing its role in securing network-layer communications. The discussion explain IPsec's foundational security features, including confidentiality, integrity, authentication, and replay protection, and how these are delivered by its constituent protocols like Authentication Header (AH) and Encapsulating Security Payload (ESP). The discussion further illuminate IPsec's operational modes (Transport and Tunnel), its reliance on the Internet Key Exchange (IKE) protocol for key management, and its specific cryptographic algorithms. Crucially, it addresses prevalent vulnerabilities, misconfigurations, and historical security incidents, highlighting the practical challenges of implementation. Finally, the discussion converge on the significant threat posed by quantum computing to IPsec's cryptographic foundations, introducing the "Harvest Now, Decrypt Later" paradigm and discussing strategies for post-quantum migration.