Multi-Dept Campus Inter-VLAN with Router-on-a-Stick

Bundle lab · $29.99

Design and implement a three-department campus edge using a single router-on-a-stick to provide inter-VLAN routing for Sales (VLAN 10), Engineering (VLAN 20), and Servers (VLAN 30). Map the addressing plan directly to router subinterfaces and build an 802.1Q trunk on the access switch. Verify end-to-end reachability and troubleshoot an allow-list drift scenario.

Learning objectives

• Translate a departmental IP addressing plan into one router-on-a-stick subinterface per VLAN.
• Configure an 802.1Q trunk between a router and a Layer-2 access switch without using SVIs.
• Create VLANs and assign host-facing access ports on a Layer-2 switch.
• Verify inter-VLAN reachability from end hosts and validate device state with IOS show commands.
• Diagnose and correct trunk allow-list drift and confirm the native VLAN posture.

Troubleshooting focus

• Diagnose and resolve the introduced fault: Trunk allow-lists, native VLAN alignment, and host VLAN assignment.
• Verify every link's interface status and IP addressing (`show ip interface brief`) and correct any interface that is down or misaddressed.
• Confirm each device's running configuration matches the lab objective, and bring any interface, route, or service that is not in its expected state back to health.
• Trace end-to-end reachability with ping/traceroute and isolate the first hop where forwarding fails.