multicast addressing
CCNA
Classful vs. Classless IP Addressing: A Complete CCNA Guide
IP addressing is the foundation of every network. Every device — a laptop, a server, an IoT sensor — needs an IP address to send and receive data. But the way those addresses are organized has changed fundamentally since the early internet. The original system, classful addressing, divided the address space into rigid classes and...
CCNA
OSPF Encapsulation: How an OSPF Message Is Wrapped for Delivery
Open Shortest Path First (OSPF) operates at the network layer, but it doesn’t travel across a network on its own — every OSPF message gets wrapped in a stack of headers before it ever leaves a router’s interface. Understanding exactly how that wrapping works, layer by layer, is essential for reading a packet capture correctly...