Question 1hardmulti select
Full question →hardmulti selectObjective-mapped
Exhibit
Switch A: channel-group 5 mode active Switch B: channel-group 5 mode passive
Two switches are connected with an EtherChannel using LACP. The bundle stays down and the physical interfaces show individual links, not a port-channel member state. Which two conditions must match on both sides for the channel to form successfully?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Best answer
The member interfaces must have compatible speed and duplex settings
Mismatched operational characteristics can prevent EtherChannel formation.
B
Distractor review
The trunk native VLAN must always be VLAN 1
The native VLAN can be other values as long as the trunks are otherwise compatible.
C
Best answer
The interfaces must use the same channel protocol and compatible LACP settings
Both sides must support the same negotiation method and be configured compatibly for the same port-channel.
D
Distractor review
The STP priority values on both switches must be identical
STP priority has nothing to do with whether an EtherChannel forms.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is believing that the trunk native VLAN must always be VLAN 1 or that STP priority values must match for EtherChannel formation. Candidates often confuse trunking parameters or STP settings with EtherChannel negotiation requirements. However, the native VLAN can be any VLAN as long as it matches on both sides, and STP priority values do not impact whether an EtherChannel forms. Misunderstanding these details leads to incorrect troubleshooting and wrong answer choices on the exam.
Technical deep dive
How to think about this question
EtherChannel is a technology that allows multiple physical Ethernet links to be combined into a single logical link to increase bandwidth and provide redundancy. Link Aggregation Control Protocol (LACP) is a dynamic protocol used to negotiate and maintain EtherChannel bundles between switches. For LACP to successfully form an EtherChannel, the physical interfaces on both sides must have compatible operational parameters such as speed and duplex settings, ensuring consistent link behavior and preventing mismatches that could cause the bundle to fail. In addition to matching speed and duplex, both sides must use the same channel protocol and compatible LACP settings. This means that both switches must be configured to use LACP (not PAgP or static EtherChannel), and their LACP modes (active or passive) must be compatible to allow negotiation. If one side uses LACP and the other uses a different protocol or static configuration, the EtherChannel will not form, and the interfaces will remain as individual links. A common exam trap is assuming that native VLAN settings or Spanning Tree Protocol (STP) priorities must match for EtherChannel formation. While trunking configurations like native VLAN should be consistent for proper traffic forwarding, they do not prevent the EtherChannel from forming. Similarly, STP priority values affect root bridge election and loop prevention but do not influence EtherChannel negotiation. Understanding these distinctions helps avoid misconfigurations and exam mistakes.
KKey Concepts to Remember
- EtherChannel bundles multiple physical Ethernet links into a single logical link to increase bandwidth and provide redundancy.
- LACP dynamically negotiates EtherChannel formation by exchanging protocol packets between switches to agree on link bundling.
- All member interfaces in an EtherChannel must have matching speed and duplex settings to ensure consistent link operation.
- Both sides of an EtherChannel must use the same channel protocol and compatible LACP settings for successful negotiation.
- LACP modes active and passive are compatible and allow negotiation, but mismatched protocols prevent EtherChannel formation.
- Trunk native VLAN settings do not prevent EtherChannel formation but must match for proper VLAN traffic forwarding.
- STP priority values influence root bridge election but do not affect whether an EtherChannel bundle forms.
- EtherChannel failure often results in physical interfaces remaining as individual links rather than joining a port-channel.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
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More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A router learns the same prefix from both OSPF and EIGRP. Which route is installed by default?
Question 2
A router shows this output: R1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/DR 00:00:34 192.168.12.2 GigabitEthernet0/0 10.1.1.3 1 2WAY/DROTHER 00:00:39 192.168.12.3 GigabitEthernet0/0 Which statement is correct?
Question 3
What is the OSPF metric called?
Question 4
A non-root switch has two uplinks toward the root bridge. One path has a lower total STP cost than the other. What role will the lower-cost uplink have?
Question 5
A router interface applies this ACL inbound: 10 deny tcp any any eq 80 20 permit ip any any A user reports that web browsing to a server by IP address fails, but ping works. Which statement best explains the behavior?
Question 6
A router learns route 198.51.100.0/24 from OSPF with AD 110 and also has a static route to the same prefix configured with AD 150. Which route is installed?
FAQ
Questions learners often ask
What does this 200-301 question test?
EtherChannel bundles multiple physical Ethernet links into a single logical link to increase bandwidth and provide redundancy.
What is the correct answer to this question?
The correct answer is: The member interfaces must have compatible speed and duplex settings — LACP active/passive is valid, but the interfaces still have to match operationally and be configured compatibly for the same bundle. Speed, duplex, trunking, and channel protocol consistency all matter.
What should I do if I get this 200-301 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
Discussion
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