5. Classful Classless IP Addresses

Learn the difference between classful and classless IP addressing — understanding how the shift from classful to classless changed the way networks are designed and how IP addresses are assigned is essential knowledge for the CCNA exam! In this video, you'll learn: What classful IP addressing is and how it defined fixed network boundaries for Class A, B, and C Why classful addressing wasted enormous amounts of IP address space What classless IP addressing is and how it removed the fixed class boundaries How CIDR allowed network prefixes of any length instead of only 8, 16, or 24 bits How classless addressing enables VLSM — assigning different subnet sizes within the same network How the move to classless addressing extended the life of the IPv4 address space How routing protocols handle classful vs classless address advertisements differently What supernetting is and how it aggregates multiple classful networks into a single route How to identify whether an address assignment is classful or classless Why classless addressing is the standard in all modern network design and routing protocols The shift from classful to classless addressing was one of the most important transitions in the history of IP networking. Understanding both systems and why the change was necessary gives you the context to understand subnetting, VLSM, CIDR, and routing protocol behavior on the CCNA exam. Connect With Us Like if this helped you Subscribe for daily CCNA content Drop your questions in the comments #systemengineer7131 #CCNA #ClassfulAddressing #ClasslessAddressing #CIDR #VLSM #IPv4 #CiscoNetworking #CCNABoost #NetworkingTutorial #CCNA2026