Cisco Certified Network Professional Practice Test 2025 - Free CCNP Exam Practice Questions and Study Guide

The VLAN ID designated for the root bridge in the primary configuration command is 24,576. This specific value is part of the 802.1D standard for spanning tree protocol, which allows network administrators to manually specify a priority value for the root bridge. The bridge priority value is combined with the VLAN ID to determine the bridge ID, which is critical in identifying the root bridge in a switched LAN environment.

In the Spanning Tree Protocol (STP), the lowest bridge ID becomes the root bridge. The bridge ID is made up of the priority (which can be set in increments of 4096) combined with the VLAN ID. When the priority is set to 24576, it is using the second default level priority, allowing network design flexibility in root bridge selection without interfering with the default bridge priority values.

Other options listed are out of the typical range for the default priority values used in VLAN configurations with STP, making them incorrect for this specific context. The standard increments for bridge priorities are based around the default value of 32768, with adjustments made typically in increments of 4096.