Build & Troubleshoot a Switched VLAN Topology
Put VLANs, 802.1Q trunking and router-on-a-stick inter-VLAN routing together across two switches and a router, then troubleshoot a broken trunk allowed-list — an end-to-end CCNA switching scenario in a simulated IOS console.
Skills you will practice
- Router-on-a-stick inter-VLAN routing; 802.1Q sub-interfaces (encapsulation dot1q); end-to-end VLAN/trunk build; structured troubleshooting of trunk allowed-VLAN lists; verification with show ip route
- show ip interface brief and show interfaces trunk
Certifications this lab maps to
This lab builds hands-on skills that appear on these certification exams. thinQtank Learning runs instructor-led training camps for each — click one to see upcoming classes.
The scenario
SW1 has Sales (10) and Engineering (20) users and a trunk up to router R1 for inter-VLAN routing (router-on-a-stick). Set up the switch side.
What you will do
- VLANs, access and trunk to the router4 steps
Create VLANs on SW1 · Access ports · Trunk to R1 · Verify the trunk
- Router-on-a-stick on R16 steps
Bring up the physical interface · Subinterface for VLAN 10 · Subinterface for VLAN 20 · Verify interfaces · …
- Verify inter-VLAN routing5 steps
Check the routing table · Connected routes · Review R1 config · End to end · …
- Troubleshoot and finalize5 steps
Check SW2 trunk · Fix the allowed VLANs · Allowed-list symptom · Verify SW2 again · …
How this lab works
A real Linux-style console. Commands run against real files, so hashes, hex dumps and comparisons give real results.
A file browser where you can place evidence into the lab, either the file provided or one of your own.
Reset a single step, a whole task or the entire lab. The environment is rebuilt so you can try again cleanly.
Progress saves after every step. Close the tab and come back later; your files and answers are waiting.