Working notes on network operations, labs, and edge triage — written for clarity, not theatre.
A practical walkthrough for NOC and network analysts: what to verify first when an edge looks healthy but something still feels off.
Working notes from a multi-switch Packet Tracer topology — access vs trunk, inter-VLAN routing, and the failure cases worth documenting.
How I structure first-pass troubleshooting at the customer edge — L1/L2 isolation, CPE checks, and when to escalate upstream.