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2.0 Switching and Network Access

EtherChannel Practice Questions

Link aggregation with PAgP and LACP.

CCNA v2.0 objective 2.1.c · objective map

Author-reviewed by LabFabric · 6 September 2026 · Report a content issue

One solved question, so you can see how these are marked

What is the main purpose of configuring an EtherChannel between two switches?

To combine multiple physical links into one logical link for extra bandwidth and redundancy, while avoiding STP blocking a redundant path

STP treats a correctly formed Layer 2 EtherChannel as one logical link, rather than selecting among its individual members. STP can still block the whole port-channel where the wider topology requires it. Aggregate capacity does not give a single flow the sum of every member's bandwidth.

Every question in the set below is marked like this. The answers stay hidden until you pick one.

Find related practice in the CCNA path
All 11 EtherChannel questions in this set

Answers and explanations appear when you work through the set above.

  1. Which command bundles interfaces g0/1 and g0/2 into port-channel 1 using LACP in active mode?

    • channel-group 1 mode active, entered on each member interface
    • channel-group 1 mode desirable, entered on each member interface
    • interface port-channel 1, then switchport mode trunk
    • etherchannel 1 mode lacp

  2. Which two LACP channel-group modes will actually negotiate and successfully form a bundle with each other?

    • active and passive
    • passive and passive
    • active and desirable
    • on and passive

  3. Which two PAgP channel-group modes will successfully negotiate and form a bundle?

    • desirable and desirable, or desirable and auto
    • auto and auto
    • active and passive
    • on and auto

  4. What does channel-group 1 mode on configure, as opposed to active or desirable?

    • It forces the interface into the bundle statically with no negotiation protocol involved at all
    • It enables PAgP only
    • It enables LACP only
    • It is identical in behavior to auto mode

  5. EtherChannel members are not bundling. A configuration comparison reveals inconsistent access VLANs among the local member ports. What should be corrected?

    • The physical cables are the wrong color
    • The member interfaces have mismatched settings, such as speed, duplex, access VLAN, or trunk configuration
    • STP is disabled on both switches
    • The switches are using different IOS versions

  6. Once member interfaces are bundled, where should ongoing configuration such as switchport mode trunk be applied for it to take effect consistently across the bundle?

    • On the logical port-channel interface, which then propagates to all bundled member interfaces
    • Individually on each physical member interface only
    • On the VLAN interface (SVI) instead
    • It cannot be changed once bundled

  7. Which command summarizes each configured EtherChannel's port-channel number, protocol in use, and the status of its member interfaces?

    • show etherchannel summary
    • show interfaces trunk
    • show spanning-tree summary
    • show channel-group brief

  8. Why can mismatched channel-group protocols, such as LACP on one switch and PAgP on the other, never form a working EtherChannel?

    • LACP and PAgP are actually the same protocol under different names
    • LACP and PAgP are separate, incompatible negotiation protocols, so a port running one cannot negotiate with a port running the other
    • PAgP is deprecated and no longer functions on any Cisco switch
    • It works fine as long as the port-channel numbers match

  9. How does EtherChannel decide which physical member link carries a given frame?

    • Frames are always sent out the lowest numbered physical port
    • A load-balancing hash, commonly based on source and/or destination MAC or IP address, deterministically maps each flow to one member link
    • Every frame is duplicated across all member links
    • It alternates strictly round robin per frame

  10. Why does bundling redundant links into an EtherChannel avoid the bandwidth waste that spanning tree would otherwise cause on those same links?

    • Because STP treats the whole bundle as a single logical link, so none of the physical members get individually blocked the way separate parallel links would
    • Because EtherChannel disables spanning tree entirely on the switch
    • Because EtherChannel bypasses Layer 2 forwarding altogether
    • Because bundled links are automatically excluded from the topology

  11. An administrator adds a third interface to an existing two-port LACP EtherChannel using channel-group 1 mode active, but the new port stays in individual status while the original two remain bundled. What should be checked first?

    • Whether the port-channel number itself is odd or even
    • Whether the new physical interface's speed, duplex, and switchport configuration match the other bundle members exactly
    • Whether LACP has a hard limit of two members per channel
    • Whether the switch needs a reload to recognize the new member