Cisco Certified Network Professional 2026 – 400 Free Practice Questions to Pass the Exam

To understand why having a different VLAN allow list is not a prerequisite for configuring EtherChannel, one must recognize the fundamental requirements for establishing an EtherChannel, which is a method of bundling multiple physical links into a single logical link to increase bandwidth and provide redundancy.

In EtherChannel configuration, the interfaces being bundled must match in specific parameters to ensure seamless operation:

- The same access VLAN needs to be set on the participating ports when dealing with access ports to ensure that they carry the same traffic.

- Duplex settings must be identical to prevent mismatch errors, which can lead to poor performance or network loops.

- Similarly, the link speed must be consistent across the interfaces, as different speeds can result in unreliable link aggregation.

In contrast, having a different VLAN allow list does not impede the ability to form an EtherChannel. VLAN allow lists primarily apply to trunk ports, defining which VLANs can pass through the trunk. Even if the allow lists differ, as long as the other prerequisites regarding speed, duplex settings, and VLAN configuration are satisfied, an EtherChannel can still be successfully configured.

Thus, the requirement for ports to have a different VLAN allow list does not impact the core mechanics of EtherChannel. The primary focus remains on matching the operational features that directly