CCNA Foundations Series: Layer 2 Day 6

Archive lab

Deploy and troubleshoot VLANs, 802.1Q trunks, and port security in a realistic small-branch ROAS design. You will stand up VLANs 10/20/99 with a hardened trunk native VLAN 999, configure sticky port security on access ports, correct a misassigned VLAN, and resolve an err-disabled port caused by a port security violation. Finish by verifying end-to-end host connectivity across VLANs.

Learning objectives

• Create and verify VLANs on Cisco Layer 2 switches and assign access ports
• Configure secure 802.1Q trunks with an explicit allowed VLAN list and a hardened native VLAN
• Implement and verify port security (sticky MAC, max MAC count, violation actions) on access ports
• Detect and remediate common Layer 2 issues including misassigned VLANs and port security errdisable
• Verify inter-VLAN connectivity using router-on-a-stick gateways and host-based testing

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.