In Spanning Tree Protocol (STP), Topology Change (TC) BPDUs are used to notify switches about network topology changes.
* The Root Bridge generates BPDUs with TC bits set, which are forwarded through the network.
* Non-root switches forward these BPDUs through their Designated Ports.
* Option A (Incorrect - Root Port): The Root Port receives BPDUs from the Root Bridge but does not forward them.
* Option B (Correct - Designated Port): Designated ports are responsible for forwarding BPDUs down the tree towards other switches.
* Option C (Incorrect - Backup Port): Backup ports are blocking and do not forward BPDUs.
* Option D (Incorrect - Alternate Port): Alternate ports are in a blocking state and do not forward BPDUs.
Thus, the correct answer is B.

The default port number for Telnet is 23. This standard port assignment allows Telnet clients to connect to Telnet servers, facilitating remote management and troubleshooting tasks on network devices. Ports are preassigned to services to streamline network communication and reduce conflicts.

* OSPFv1 (B): Was an experimental version, not widely used.
* OSPFv2 (C): Used for IPv4 networks, does not support IPv6.
* OSPFv3 (D): Specifically designed for IPv6 networks and includes additional features like security and address scope handling.
* OSPFv4 (A): This version does not exist.
Thus, the correct answer is D (OSPFv3).

This explanation was already provided earlier. Please refer to question 13 at the start.

Detailed Explanation:RSTP (Rapid Spanning Tree Protocol) employs a synchronization mechanism with the proposal/agreement handshakes to prevent loops during topology changes. By synchronizing states between switches, RSTP avoids temporary loops while quickly transitioning ports to the forwarding state. (Reference:
HCIA-Datacom Training Material, RSTP Mechanisms and Synchronization)