Ping Labz

All 8 OSPF neighbor states (Down, Attempt, Init, 2-Way, ExStart, Exchange, Loading, Full), what triggers each transition, and what to check when a neighbor is stuck.

VLAN, subnet, and broadcast domain are not the same thing. The layer each lives at, the relationships between them, and the misalignment that breaks hosts silently.

SD-WAN in five minutes: what it is, what it replaces, the four-plane architecture, transport-independent overlays, and how it stacks against traditional MPLS WANs.