Learn the complete subnet ranges for IPv4 Class A, B, and C networks. This guide explains default masks, CIDR notation, address ranges, and practical subnetting examples for networking and cybersecurity professionals. IPv4 addressing remains a foundational concept in networking, security engineering, and system administration. Despite the shift toward IPv6, understanding IPv4 subnet ranges and classful addressing is essential for architects, administrators, and analysts working with enterprise networks, firewalls, cloud systems, and compliance-driven environments. This guide provides a clear, structured overview of IPv4 class ranges, default subnet masks, CIDR blocks, and commonly used subnet ranges for Class A, Class B, and…