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IntermediatePublished 2026-06-30

CCNA: Native VLAN & Untagged Traffic on 802.1Q

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Hands-on CCNA switching lab focused on the native VLAN and tagging behavior on 802.1Q trunks. Users in one VLAN currently cannot reach their peers across a switch-to-switch trunk; you will standardize the native VLAN away from VLAN 1 to a dedicated parking VLAN, diagnose and correct the trunk configuration, verify the untagged VLAN on both ends, and confirm same-VLAN host reachability across the trunk.

Track
Est. time
55 minutes
Difficulty
Intermediate
Topics

Learning objectives

  • Explain how 802.1Q tagging works and why exactly one VLAN rides untagged (the native VLAN).
  • Create user VLANs and place end-host access ports correctly on Layer-2 switches.
  • Configure an 802.1Q trunk between switches and move the native VLAN off VLAN 1 to a dedicated parking VLAN.
  • Harden trunks by aligning the allowed VLAN list and disabling DTP negotiation.
  • Use show interfaces trunk and related commands to verify native VLAN, allowed VLANs, and operational trunk state.
  • Troubleshoot connectivity when a required VLAN is omitted from a trunk allow-list or when the native VLAN is inconsistent.

Troubleshooting focus

  • Native VLAN left as VLAN 1 or set inconsistently between trunk ends
  • Required VLAN not permitted in the trunk's allowed list
  • Host access port assigned to the wrong VLAN
  • Forgetting to create a VLAN on both switches' VLAN databases
  • Assuming a working trunk despite DTP/nonegotiate or pruning changes

Topology

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Learn VLANs, Trunking & Inter-VLAN RoutingWhat Is a VLAN? VLANs Explained for Beginners

Grade your work

How this lab is graded
  • Build it your way. Where a lab lets you choose a value — a VLAN name, an interface description — grading checks that you configured it, not which name you picked. Names that another line has to reference, like an ACL applied with access-class, are stated in the guide and do have to match.
  • Addresses, modes and protocol keywords are exact. An IP address, a subnet mask, switchport mode trunk, an encapsulation — these carry the meaning of the lab, so they are graded as written in the guide.
  • Grading reads your saved configuration. Export the lab from CML after you have configured it, and make sure anything you set is in the running-config — a change that only exists in a terminal session never reaches the grader.
  • You can submit as many times as you like. Your best score stands, and each attempt tells you which checks passed so you can work the gaps.
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