Goal: build a small multi-switch topology where access ports stay quiet, trunks carry only intended VLANs, and inter-VLAN routing behaves predictably.
Topology intent
Two access switches, one Layer-3 distribution (or router-on-a-stick). Separate user and management VLANs. One deliberately misconfigured trunk to practice spotting native-VLAN mismatch symptoms.
What I am verifying
Access ports in the correct VLAN. Trunk allowed list is explicit — not "all". SVI or subinterface addressing matches the design. Hosts in VLAN A cannot casually reach VLAN B without the L3 hop.
Failure cases to document
Wrong access VLAN. Trunk missing a VLAN. Native VLAN mismatch. Inter-VLAN route present but ACL blocking return traffic. These are the notes that matter more than a green diagram.
Status
In progress. Diagrams and command snippets will land here as the lab stabilizes.