Cisco Certified Network Associate (CCNA) Practice Exam

What is the closest port to the Root Bridge called in STP?

1. Designated Port

2. Root Port

3. Backup Port

4. Blocked Port

The correct answer is: Root Port

The closest port to the Root Bridge in Spanning Tree Protocol (STP) is referred to as the Root Port. This is the port on a non-root bridge that has the lowest path cost to the Root Bridge, meaning it is the most efficient path available for forwarding traffic toward the Root Bridge. The concept of the Root Port is essential in managing how data frames are sent across a network while preventing loops that could occur in a redundant switch topology. In STP, every switch determines its Root Port based on the cost of the paths to the Root Bridge, which is established when the STP topology is calculated. The port is not only significant for direct data forwarding, but it also plays a critical role in maintaining network stability since non-root switches utilize the Root Port to communicate upstream toward the Root Bridge. Other options mention different types of ports within the STP framework, including Designated Port, which is responsible for forwarding traffic on a segment; Backup Port, which serves as a secondary option if the Designated Port fails; and Blocked Port, which does not forward traffic to prevent loops. However, none of these terms represent the specific port that provides the closest connection to the Root Bridge, making the Root Port the correct answer.