CCNA Switching and Network Access Practice Question
Network Topology
You are connected to SW1. The current configurations of interfaces GigabitEthernet0/1 and GigabitEthernet0/2 are as follows:
Gi0/1: speed 100, duplex half, switchport access vlan 10 Gi0/2: speed 1000, duplex full, switchport access vlan 20
The port-channel interface 1 does not exist. Configure a LACP EtherChannel between SW1 and SW2 using these two interfaces, with port-channel 1 and mode active on both sides. Ensure the channel forms by resolving any speed/duplex or VLAN mismatches. After configuration, verify with 'show etherchannel summary'.
⚠ Common exam trap
Cisco exam traps often test the requirement for identical speed, duplex, and VLAN on all EtherChannel member interfaces. Do not assume LACP can negotiate mismatches; it only handles aggregation, not physical or VLAN parameters.
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
✓
The EtherChannel will not form because the physical interfaces have mismatched speed/duplex and VLAN assignments. You must configure both interfaces with the same speed (1000), duplex (full), and access VLAN (10), then apply channel-group 1 mode active on each.
The EtherChannel fails because member interfaces have mismatched speed/duplex (Gi0/1 is 100/half, Gi0/2 is 1000/full) and different VLANs (VLAN 10 vs 20). Additionally, the port-channel interface and physical interfaces must have matching VLAN assignments. To fix, unify both physical interfaces to the same speed (1000), duplex (full), and access VLAN (10). Then set channel-group mode active on each physical interface. Finally, ensure the port-channel interface also uses VLAN 10. Verify with 'show etherchannel summary' which should show the port-channel as SU (in use).
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
The EtherChannel will not form because the physical interfaces have mismatched speed/duplex and VLAN assignments. You must configure both interfaces with the same speed (1000), duplex (full), and access VLAN (10), then apply channel-group 1 mode active on each.
Why this is correct
This is correct because LACP requires all member interfaces to have identical speed, duplex, and VLAN configuration. Mismatches cause the channel to fail. The fix is to unify these parameters and then set channel-group mode active on both interfaces.
- ✗
The EtherChannel will form successfully because LACP active mode negotiates the channel regardless of speed/duplex or VLAN differences.
Why it's wrong here
This is incorrect. LACP active mode only enables the negotiation process; it cannot override Layer 1 or Layer 2 mismatches. The LACP protocol requires all member interfaces to have identical speed, duplex, and VLAN membership, and if these parameters differ, the channel negotiation fails and the port-channel interface remains down. In practice, the physical interfaces would not be bundled, and the switch would report an error or keep the ports as individual access ports.
- ✗
The EtherChannel will not form because the port-channel interface must be configured with the same VLAN as the physical interfaces, but the physical interfaces can have different speeds.
Why it's wrong here
This statement is wrong because speed and duplex must match across all EtherChannel members; you cannot have different speeds in the same channel. While the port-channel interface does need to be configured with the correct VLAN, the physical interfaces themselves must also have consistent VLAN assignments, and an access VLAN mismatch is a common reason for the channel to fail. The actual fix is to align all physical interface parameters, then configure the port-channel and apply channel-group mode active.
- ✗
The EtherChannel will form successfully because the port-channel interface inherits the VLAN from the first physical interface added, so no additional configuration is needed.
Why it's wrong here
This is incorrect because the port-channel interface does not automatically inherit VLAN settings from a physical member interface. Each physical interface in the EtherChannel must be explicitly configured with the same VLAN and other parameters, and the channel-group command must be applied to each interface. Without manual configuration of the port-channel interface and matching VLANs on all members, the channel will not form; the only inheritance that occurs is the logical port-channel inherits the configuration from the first member only if the member is added first, but that is not a valid or reliable method, and Cisco recommends configuring the port-channel interface directly.
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.
✓The EtherChannel will not form because the physical interfaces have mismatched speed/duplex and VLAN assignments. You must configure both interfaces with the same speed (1000), duplex (full), and access VLAN (10), then apply channel-group 1 mode active on each.Correct answer▾
Why this is correct
This is correct because LACP requires all member interfaces to have identical speed, duplex, and VLAN configuration. Mismatches cause the channel to fail. The fix is to unify these parameters and then set channel-group mode active on both interfaces.
✗The EtherChannel will form successfully because LACP active mode negotiates the channel regardless of speed/duplex or VLAN differences.Wrong answer — click to see why▾
Why this is wrong here
LACP active mode only enables negotiation, but it does not resolve underlying parameter mismatches. The interfaces must still have consistent speed, duplex, and VLAN configuration.
Why candidates choose this
Candidates may think that LACP's negotiation capability can automatically adjust or ignore mismatches, but it only handles aggregation, not physical or VLAN parameters.
✗The EtherChannel will not form because the port-channel interface must be configured with the same VLAN as the physical interfaces, but the physical interfaces can have different speeds.Wrong answer — click to see why▾
Why this is wrong here
All member interfaces must have identical speed and duplex settings. Even if VLANs match, speed mismatch will cause the channel to fail.
Why candidates choose this
Candidates might know that VLAN consistency is required but underestimate the importance of speed/duplex matching, thinking LACP can handle speed differences.
✗The EtherChannel will form successfully because the port-channel interface inherits the VLAN from the first physical interface added, so no additional configuration is needed.Wrong answer — click to see why▾
Why this is wrong here
The port-channel interface is a logical interface that requires its own VLAN configuration. Physical interfaces must have identical VLAN assignments; otherwise, the channel will not form.
Why candidates choose this
Candidates may think that adding physical interfaces to a port-channel automatically synchronizes VLAN settings, but in reality, mismatches cause the channel to fail.
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?”
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Key term
Switchport
A switchport is a physical or virtual interface on a network switch that connects devices like computers, printers, or other switches to a local area network.
Key term
Link Aggregation Control Protocol
Link Aggregation Control Protocol (LACP) is a standard protocol that automatically bundles multiple physical network links into a single logical link to increase bandwidth and provide redundancy.
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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.