IntermediatePublished 2026-08-03
CCNA: EtherChannel Mode Matching (PAgP, LACP, Static)
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CCNA exam domain: Network Access
Hands-on CCNA EtherChannel repair lab. Two uplinks between a distribution and an access switch are intended to form a single port-channel trunk carrying VLAN 10. The starter ships with a real mode mismatch across the bundle and an allow-list error, so the Port-channel stays down and hosts cannot talk. Learners diagnose the symptom and standardize on one protocol family (PAgP, LACP, or Static) and correct trunking so VLAN 10 forwards end-to-end.
Learning objectives
- Identify EtherChannel negotiation families (PAgP vs LACP) and compatible mode pairings
- Read EtherChannel status flags and suspended/individual member states
- Normalize trunking on a Port-channel (native VLAN, allow-list, nonegotiate)
- Verify from end hosts and switches that the bundle forwards VLAN traffic
Troubleshooting focus
- If Port-channel 1 remains down: Compare protocol families: do both ends use the same negotiation (LACP vs PAgP vs Static)? Incompatible families do not form.; Check mode pairing compatibility: e.g., active must see active or passive for LACP; desirable must see desirable or auto for PAgP; static requires on/on.; Confirm both physical members reference the same channel-group number and the same Port-channel interface.
- If the bundle comes up but hosts still cannot ping: Inspect the Port-channel trunk allow-list: does it include VLAN 10 on both ends?; Verify the native VLAN setting matches (use 999 on both ends to avoid untagged traffic mismatch).; Ensure VLAN 10 exists on all switches along the path and that access ports toward hosts are in VLAN 10.
- If only one member seems to carry traffic or you see errdisable/suspended: Look for per-port inconsistencies (speed/duplex, allowed VLANs placed on the physical member instead of the Port-channel, or mismatched channel-group commands between members).
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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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