Configuring Layer 3 EtherChannel with LACP

200-301 By islever Editorial Last updated

Short answer

CD Configure the physical interface with channel-group mode active to use the open-standard LACP protocol, and configure the port-channel interface with no switchport to enable Layer 3 routing.

Question

Which two command sequences must be configured on a switch to establish a Layer 3 EtherChannel with an open-standard protocol? (Choose two.)
  1. interface GigabitEthernet0/0/1 channel-group 10 mode auto
  2. interface GigabitEthernet0/0/1 channel-group 10 mode on
  3. interface port-channel 10 no switchport ip address 172.16.0.1 255.255.255.0 Correct Answer
  4. interface GigabitEthernet0/0/1 channel-group 10 mode active Correct Answer
  5. interface port-channel 10 switchport switchport mode trunk

Key Takeaways

The question tests two distinct concepts: identifying LACP as the open standard (requiring 'active' or 'passive' mode) and understanding that Layer 3 EtherChannels require the 'no switchport' command on the logical port-channel interface.

Learn how to configure a Layer 3 EtherChannel using the open-standard LACP protocol. The correct commands involve setting the physical interface to 'active' mode and converting the port-channel to a routed interface.

Common mistake: Candidates often choose Option B ('mode on'), which creates a static EtherChannel but ignores the 'open-standard' requirement. Others may incorrectly keep the interface in Layer 2 mode (Option E), failing to apply 'no switchport' to enable IP routing.

Expert Analysis

To establish a Layer 3 EtherChannel using an open-standard protocol, you must select the correct negotiation mode and correctly configure the logical interface as a routed port. The open standard for link aggregation is Link Aggregation Control Protocol (LACP). On Cisco switches, LACP uses two modes: 'active' (actively initiates negotiation) and 'passive' (responds to negotiation). To ensure the channel forms reliably, at least one side must be set to 'active'. Therefore, configuring a physical interface with channel-group 10 mode active (Option D) satisfies the requirement for an open-standard protocol. Options A ('auto') refers to PAgP, which is a Cisco proprietary protocol, and Option B ('on') forces the channel without negotiation, which does not use an open standard.

Once the physical interfaces are bundled, the resulting Port-Channel interface (e.g., interface port-channel 10) defaults to Layer 2 switching behavior. To make it a Layer 3 EtherChannel, you must convert it to a routed port by issuing the no switchport command. This allows you to assign an IP address directly to the bundle. Option C (interface port-channel 10 no switchport ip address...) correctly performs this conversion and configuration. While some comments note that no switchport can sometimes fail if applied after the channel group is formed on certain IOS versions, in the context of certification exams, applying these commands to the port-channel interface is the standard method for defining a Layer 3 aggregate. Option E keeps the interface in Layer 2 mode, making it incorrect for a Layer 3 requirement.

Exam Strategy

When asked for an 'open-standard' protocol, immediately eliminate Cisco proprietary options like PAgP ('auto'). For Layer 3 EtherChannels, always look for the 'no switchport' command on the port-channel interface. Remember that LACP requires 'active' or 'passive' on at least one end; 'on' is manual/static only.

Frequently Asked Questions

What is the difference between LACP and PAgP?

LACP (Link Aggregation Control Protocol) is an IEEE open standard (802.3ad) supported by most vendors. PAgP (Port Aggregation Protocol) is a Cisco proprietary protocol. The question specifies 'open-standard,' so LACP is the only valid choice.

Why do I need 'no switchport' for a Layer 3 EtherChannel?

By default, Port-Channel interfaces operate as Layer 2 switch ports. The 'no switchport' command converts the interface into a routed port, allowing you to assign an IP address and perform Layer 3 forwarding.

Can I use 'mode on' for an EtherChannel?

Yes, 'mode on' creates a static EtherChannel without negotiation. However, it is not an 'open-standard' protocol because it doesn't use LACP or PAgP. It also requires both sides to be manually configured as 'on'.

More 200-301 FAQ →

Community Votes

C
47%
D
41%
B
9%
E
3%

47% of anonymous learners picked answer C. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 66 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 30 of 66

  1. Dave861 👍 72
    We can answer this by discarding incorrect answers we need to use an open standard IE LACP The option "A" is discarded: PAgP configuration The option "B" is discarded: manual configuration ("On" mode) The option "C" is configuration that LACP uses. The option "D" is configuration that LACP uses. The option "E" is discarded: It is configuration of trunk mode, not Etherchannel C and D correct.
  2. Ali526 👍 24
    Not only that; the question asks for layer3. When you put in switchport, it becomes layer 2.
  3. dori 👍 18
    The right answer should be C and D
  4. sojCCIE 👍 8
    Answr=CD The port-channel must be created then 'no sw' and ip addr to become a layer 3 bundled port
  5. diazed 👍 7
    C & D are the correct answers, please take a look in the following url in case of any doubt: https://learningnetwork.cisco.com/s/question/0D53i00000XANAoCAP/question-on-layer-3-channelgroup
Show 25 more comments
  1. wizcas 👍 6
    If I may correct "E": there is "switchport" twice, which is an invalid command. You actually can do access/trunk config on an EtherChannel and why wouldn't you when using VLANs. Otherwise, good statement!
  2. MikeRP 👍 6
    “C&D” correct answer
  3. ITstudent123 👍 5
    You must use the no switchport command if you want to activate L3 Etherchannel on a switch. And "mode active" refer to LACP, which is an open-standard protocol So right answers are C and D
  4. ptfish 👍 5
    C: interface port-channel 10 no switchport ip address 172.16.0.1 255.255.255.0 D: interface GigabitEthernet0/0/1 channel-group 10 mode active
  5. hokieman91 👍 5
    C & D are correct - "Layer 3" EtherChannel is the giveaway in this question-
  6. Heymannicerouter 👍 5
    Bold move posting a braindump question on a Cisco site.
  7. Cristy 👍 5
    C and D should be the right answers
  8. Ebenezer 👍 5
    The correct answers are C and D.
  9. Gere 👍 5
    C&D” correct answer
  10. LilGhost_404 👍 4
    A. interface GigabitEthernet0/0/1, channel-group 10 mode auto. (incorrect.. this is not open) B. interface GigabitEthernet0/0/1, channel-group 10 mode on. (incorrect this is not open) C. interface port-channel 10, no switchport, ip address 172.16.0.1 255.255.255.0 (correct it puts the po in L3) D. interface GigabitEthernet0/0/1, channel-group 10 mode active. (correct, uses LACP... this is open) E. interface port-channel 10, switchport, switchport mode trunk. (incorrect Switchport puts them in L2) C and D are correct!
  11. Ali526 👍 4
    E is absolutely WRONG. The question is very clear about "Layer 3 EtherChannel". Layer 3 EC will have IP address and also will need "NO switchport" command. The answer E has "switchport", actually twice, and that'll guarantee this as Layer 2, not Layer 3. CD correct.
  12. admin1982 👍 4
    The correct answer is C & D. Active/ Passive modes for an open-standard protocol is LACP. When you type the "no switchport" command on a Layer 3 switch, it turns that port into a non-switching port so you can add and IP address, e.g. etherchannel-group 10. C and D
  13. mrsiafu 👍 4
    Layer 3 EtherChannel: Step 1 config physical interface 1. add channel-group 2. no switchport Step 2 Config Port-channel 1. interface port-channel 2. no switchport 3. ip address
  14. Claudiu1 👍 4
    dude, he uses those commands to create L2 Etherchannels with the access switches. Did you even watch the video you referenced?
  15. sinear 👍 4
    Answer E is wrong cause in L3 ports must be in routed mode, so it should be "no switchport"
  16. Ali526 👍 4
    But the question asks for layer3. When you put in switchport, it becomes layer 2.
  17. Whippy29 👍 4
    Question states layer 3, has to be C
  18. HarLikon 👍 4
    Aswers are C,D
  19. elixirwell 👍 3
    ChatGPT says, The two command sequences that must be configured on a switch to establish a Layer 3 EtherChannel with an open-standard protocol are: B. interface GigabitEthernet0/0/1 channel-group 10 mode on D. interface GigabitEthernet0/0/1 channel-group 10 mode active Option A (interface GigabitEthernet0/0/1 channel-group 10 mode auto) sets the interface to automatically negotiate the mode of the EtherChannel, which may not be desirable. Option C (interface port-channel 10 no switchport ip address 172.16.0.1 255.255.255.0) configures a Layer 3 interface for the EtherChannel, but it does not establish the EtherChannel itself. Option E (interface port-channel 10 switchport switchport mode trunk) configures the EtherChannel interface as a trunk, but it does not establish the EtherChannel itself.
  20. kimi7 👍 3
    trunking is layer 2 tech. it allows multiple vlans over same interface and thats it. here is layer 3 eth in question and layer 3 means ip adresses. so C and D
  21. kimi7 👍 3
    anyway where is this sequence used like this: interface port-channel 10 switchport switchport mode trunk why switchport twice?
  22. promaster 👍 3
    The right answer should be C and D. you need to enabled "no switchport" because your setting up Layer 3 etherchannel.
  23. Nhan 👍 3
    Given answer are correct since the question is asking for open standard protocol which is active/passive
  24. Rockrl 👍 3
    C&D are the correct answer, Layer 3 etherchannel must be configure with noswitchport command
  25. ZUMY 👍 3
    C & D are Correct why C: For Layer 3 ether channel we need to run NO SWITCHPORT command

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