Cisco Certified Network Professional Practice Test 2025 – Your All-in-One Guide to Exam Success!

The command "Instance instance-id vlan vlan-list" in Multiple Spanning Tree (MST) configuration serves the essential function of mapping specific VLANs to a defined MST instance. This mapping is crucial because MST allows multiple VLANs to share the same spanning tree instance, thus optimizing the network design and reducing the overall complexity associated with managing multiple spanning trees. By using this command, network administrators can control which VLANs are included in each MST instance, enabling customization of traffic patterns and redundancy features.

This connection between VLANs and MST instances allows for more efficient network resource usage and can lead to improved performance in a complex network environment where different VLANs may have distinct requirements and behaviors. Each MST instance operates independently, but the ability to group VLANs under one instance means that redundancy and failover capabilities can be tailored according to specific VLAN needs.

In contrast, the other options pertain to different aspects of MST configuration. For instance, defining the maximum number of instances or configuring timers would not involve associating VLANs directly with an instance, and setting priority relates to determining which instance wins in a root election process, but does not involve the direct mapping of VLANs.