This paper provides a comprehensive review of
secured network infrastructure, encompassing fundamental networking
concepts, prevalent cyber threats, and advanced defense
mechanisms. this study elucidates the evolution of network
security from basic packet filtering firewalls to sophisticated
Next-Generation Firewalls (NGFWs), Intrusion Detection and
Prevention Systems (IDS/IPS), and Virtual Private Networks
(VPNs). It further examines various network topologies, routing
protocols, and the role of modern simulation tools like Packet
Tracer and GNS3 in understanding network behavior and
vulnerabilities. The paper categorizes common network attacks
such as Denial of Service (DoS), Man-in-the-Middle (MitM), SQL
Injection, and Zero-Day Exploits, highlighting their impact on
network integrity and availability. The objective is to synthesize
this information into a cohesive framework that underscores
the critical importance of a multi-layered security approach in
safeguarding contemporary digital environments. This review
aims to serve as a foundational resource for researchers and practitioners
seeking to understand and implement robust network
security strategies against an ever-evolving threat landscape. In
doing so, it aligns with global sustainable development efforts by
reinforcing the resilience and reliability of digital infrastructure
essential for sustainable industry and innovation.
 

network security, secured network infrastructure, cyber threats, NGFW, IDS/IPS, VPN, DoS/DDoS, Zero Trust, AI/ML security