Cisco Certified Network Associate (CCNA) Practice Exam 2026 - Free CCNA Practice Questions and Study Guide

The correct designation for the Spanning Tree Protocol (STP) is indeed 802.1D. This is the standard established by the Institute of Electrical and Electronics Engineers (IEEE) that defines the operation of Spanning Tree Protocol, which helps prevent loops in networks by creating a logical topology. STP facilitates the creation of a tree structure from multiple switched network segments, ensuring that only one active path exists between two network devices.

Understanding the context of the other options highlights their relevance in networking standards but confirms that they do not relate to STP. For example, 802.1w pertains to Rapid Spanning Tree Protocol (RSTP), which is an evolution of STP aimed at improving convergence times. Options like 802.2 and 802.3 are associated with different networking protocols; specifically, 802.2 is related to Logical Link Control, and 802.3 defines Ethernet standards. This clearly positions 802.1D as the correct choice regarding the original Spanning Tree Protocol.