CCNA Switching and Network Access Practice Question
Network Topology
You are connected to SW1. An EtherChannel between SW1 and SW2 using LACP must be established on interfaces GigabitEthernet0/1 and GigabitEthernet0/2. Currently, the channel is not forming. Inspect the provided configuration and output, then apply the necessary commands on SW1 to resolve the issue and bring up the Port-Channel interface.
⚠ Common exam trap
Do not focus solely on LACP mode mismatches; always check physical parameters (speed, duplex) and VLAN consistency first. Mismatched native VLANs are a common cause of EtherChannel failures.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Configure both interfaces with speed 1000, duplex full, and switchport access vlan 1.
The EtherChannel failed because the two member interfaces on SW1 have mismatched speed (Gi0/1: 1000 Mbps, Gi0/2: 100 Mbps) and duplex (Gi0/1: full, Gi0/2: half), and their native VLANs differ (Gi0/1: VLAN 1, Gi0/2: VLAN 10). LACP requires all bundled ports to have identical speed, duplex, and VLAN configuration. To fix, on SW1 configure both interfaces with consistent settings: set speed 1000, duplex full, and switchport access vlan 1 (or a common trunk native VLAN). Also ensure both sides use the same LACP mode (both active or active/passive); here SW2's Gi0/2 is passive, which is acceptable with SW1's active, so the primary issue is the mismatched physical and VLAN parameters. After correction, the channel will form.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Configure both interfaces with speed 1000, duplex full, and switchport access vlan 1.
Why this is correct
This is correct because LACP requires all member interfaces to have identical speed, duplex, and VLAN configuration. The mismatched settings (Gi0/1: 1000/full/VLAN1, Gi0/2: 100/half/VLAN10) prevent the EtherChannel from forming. Applying consistent settings resolves the issue.
- ✗
Change the LACP mode on SW1's Gi0/2 from active to passive.
Why it's wrong here
This is incorrect because the LACP mode mismatch is not the primary issue; SW2's Gi0/2 is passive and SW1's Gi0/2 is active, which is a valid combination (active/passive). Changing to passive would not fix the speed/duplex/VLAN mismatches.
- ✗
Configure both interfaces with speed 100, duplex half, and switchport access vlan 10.
Why it's wrong here
This is incorrect because while it would make the interfaces consistent, it uses suboptimal settings (100/half) that would degrade performance. The correct fix should use the higher speed and full duplex (1000/full) to match the faster interface.
- ✗
Remove the switchport access vlan command from both interfaces and configure them as trunk ports with native vlan 1.
Why it's wrong here
This is incorrect because the issue is mismatched VLANs, not the interface mode. Changing to trunk with native VLAN 1 would still leave the speed/duplex mismatch unresolved, and the native VLAN must match on both sides. The current configuration shows access ports, so converting to trunk is unnecessary.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.
✓Configure both interfaces with speed 1000, duplex full, and switchport access vlan 1.Correct answer▾
Why this is correct
This is correct because LACP requires all member interfaces to have identical speed, duplex, and VLAN configuration. The mismatched settings (Gi0/1: 1000/full/VLAN1, Gi0/2: 100/half/VLAN10) prevent the EtherChannel from forming. Applying consistent settings resolves the issue.
✗Change the LACP mode on SW1's Gi0/2 from active to passive.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error is assuming that LACP mode must match on both sides; active/passive is acceptable.
Why candidates choose this
Candidates may think both sides need the same LACP mode, but active/passive is a common valid pairing.
✗Configure both interfaces with speed 100, duplex half, and switchport access vlan 10.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error is that the solution should aim for optimal performance, not just consistency; using 100/half is technically possible but not the best practice.
Why candidates choose this
Candidates might think any consistent configuration works, but the exam expects the best practice of using the higher speed and full duplex.
✗Remove the switchport access vlan command from both interfaces and configure them as trunk ports with native vlan 1.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error is that trunking does not fix speed/duplex mismatches, and the native VLAN must be consistent.
Why candidates choose this
Candidates may think trunking is required for EtherChannel or that native VLAN mismatch is the only issue, overlooking the physical layer mismatches.
Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Visual reference
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Related to this question
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Key term
Native VLAN
A native VLAN is the default VLAN assigned to a trunk port that carries untagged traffic for backwards compatibility with devices that do not understand VLAN tagging.
Key term
Interface
An interface is a point of connection or interaction between two systems, devices, or software components that allows them to exchange information or signals.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 200-301 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 200-301 exam.