In spanning tree protocol, which switch is considered the root of the tree?

In spanning tree protocol, which switch is considered the root of the tree?

• A. Root Bridge
• B. Designated Bridge
• C. Blocked Port
• D. Alternate Port

Answer: (A)

In Spanning Tree Protocol, the tree is built around a single root switch, chosen by comparing Bridge IDs advertised in BPDUs. A Bridge ID combines a configurable priority with the switch’s MAC address; the lower BID wins, so the switch with the smallest BID becomes the root. Once elected, the root bridge has no root port; all its ports are designated ports for their segments. Other switches select one root port that provides the best path toward the root, while remaining ports on those switches become designated ports or are blocked to prevent loops. Alternate or blocked ports exist as backup paths when multiple routes to the root exist. So, the switch with the lowest Bridge ID is the root of the tree.

In Spanning Tree Protocol, the tree is built around a single root switch, chosen by comparing Bridge IDs advertised in BPDUs. A Bridge ID combines a configurable priority with the switch’s MAC address; the lower BID wins, so the switch with the smallest BID becomes the root. Once elected, the root bridge has no root port; all its ports are designated ports for their segments. Other switches select one root port that provides the best path toward the root, while remaining ports on those switches become designated ports or are blocked to prevent loops. Alternate or blocked ports exist as backup paths when multiple routes to the root exist. So, the switch with the lowest Bridge ID is the root of the tree.