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IntermediatePublished 2026-07-02

Layer-2 Trunk EtherChannel Carrying Multiple VLANs

Bundle lab

Build a two-link LACP EtherChannel between SW1 and SW2 and convert the Port-channel into an 802.1Q trunk that explicitly carries VLANs 40 and 41. Validate end-to-end host reachability across VLAN 40 and confirm the trunk’s allowed VLAN list and switchport mode on the logical port-channel. Emphasis: deterministic EtherChannel configuration on member interfaces, correct trunking on the Port-channel, and verification with IOS show commands.

Track
Est. time
55 minutes
Difficulty
Intermediate
Topics

Learning objectives

  • Create VLANs 40 and 41 on both switches and place access ports accordingly.
  • Bundle Ethernet0/0 and Ethernet0/1 with LACP using channel-group 4 mode active on both SW1 and SW2.
  • Configure Port-channel4 as an 802.1Q trunk and restrict its allowed VLANs to 40 and 41.
  • Harden trunks by setting a non-default native VLAN and disabling DTP negotiation.
  • Verify EtherChannel state and trunk operation with IOS show commands and confirm host reachability in VLAN 40.

Troubleshooting focus

  • Detect and resolve VLAN allow-list drift on the trunk that prunes a required VLAN.
  • Identify and correct native VLAN mismatches on trunks.
  • Find and fix incorrect access VLAN assignments on host-facing ports.

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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.
  • Scored something you believe is correct? Use Report an issue on this page — that is exactly how the grading fixes in the changelog got found.

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