350-401 Question 130
Select 3You are troubleshooting an EtherChannel configuration between Switch A and Switch B. The EtherChannel is configured using LACP, but the ports remain in the 'individual' state, and the EtherChannel is not forming. Which of the following could be the cause of the issue?
- A
Mismatched port speed or duplex settings between Switch A and Switch B
- B
The EtherChannel group is configured in 'on' mode instead of LACP
- C
One of the links in the EtherChannel is configured as a trunk while the other is configured as an access port
- D
LACP is disabled globally on Switch A
- E
The EtherChannel's native VLAN is mismatched between Switch A and Switch B
Show answer and explanation
Correct answers: A, C, D
Explanation
For LACP-based EtherChannels, all member ports must have consistent configurations, including speed, duplex, and port mode. Additionally, LACP must be enabled globally for the protocol to function. Static EtherChannels configured in 'on' mode do not use LACP, so this is an irrelevant scenario for the given problem. A native VLAN mismatch can cause traffic issues but does not prevent EtherChannel formation.
- A. Correct.
Correct. For LACP to work, all member ports in the EtherChannel must have the same speed and duplex settings. Mismatched settings can prevent LACP from forming the bundle.
- B. Incorrect.
Incorrect. If the EtherChannel is configured in 'on' mode, LACP is not used at all, and a static EtherChannel may form instead. This is unrelated to LACP-specific troubleshooting.
- C. Correct.
Correct. LACP requires uniform configuration across member ports, including port mode (trunk or access). A mismatch will prevent the EtherChannel from forming.
- D. Correct.
Correct. If LACP is disabled globally on a switch, the protocol will not function, and the EtherChannel will not form.
- E. Incorrect.
Incorrect. While a native VLAN mismatch can cause communication issues, it does not prevent the formation of the EtherChannel using LACP.