Trunk Allowed-VLAN Pruning Across L2 Switches

Bundle lab · $29.99

Configure VLANs and access ports on two Layer-2 switches, build 802.1Q trunks (with hardened native VLAN and an explicit allowed list), validate end-to-end reachability, intentionally prune a VLAN from the inter-switch trunk to observe segmentation, then restore the correct allow-list. Includes realistic router-on-a-stick gateways for VLAN 10/20/99 and switch management on VLAN 99.

Learning objectives

• Configure and verify VLANs and access ports on Layer-2 switches
• Implement and verify 802.1Q trunks between switches
• Control trunked VLANs using 'switchport trunk allowed vlan' and a hardened native VLAN
• Detect and resolve connectivity loss caused by trunk allow-list misconfiguration
• Validate intra-VLAN and inter-VLAN reachability with host tests
• Use show interfaces trunk, VLAN/SVI verification, and host pings for troubleshooting

Troubleshooting focus

• 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.