The rapid evolution of networked systems and the increasing sophistication of cyber threats have made modern network security architectures a critical component of organizational IT strategies. This study provides a comprehensive review of contemporary network security architectures, emphasizing their design principles, technologies, and implementation strategies. The paper explores traditional security models, such as perimeter-based firewalls, alongside modern approaches including zero trust architecture, software-defined networking (SDN) security, and cloud-native security frameworks. The study examines key technologies, such as intrusion detection and prevention systems (IDPS), network access control (NAC), encryption protocols, and advanced threat intelligence platforms. It also highlights the integration of artificial intelligence (AI) and machine learning (ML) for anomaly detection, predictive threat analysis, and automated response mechanisms. Critical challenges, including scalability, performance overhead, complexity, and compliance, are analyzed along with practical solutions and best practices for deploying robust, adaptive, and resilient security architectures. The review underscores that modern network security architectures must balance protection, usability, and agility to effectively mitigate evolving threats while supporting dynamic enterprise networks.\n\n