CREST Practitioner Security Analyst (CPSA) Practice

Which layer of the network does the Dynamic Trunking Protocol operate on?

1. Layer 1

2. Layer 2

3. Layer 3

4. Layer 4

The correct answer is: Layer 2

Dynamic Trunking Protocol (DTP) operates at Layer 2 of the OSI model, which is the data link layer. This layer is responsible for node-to-node data transfer and addressing, as well as for the framing and handling of error detection and correction. DTP is specifically used to negotiate and manage trunk links between switches, allowing them to carry traffic for multiple VLANs over a single physical link by dynamically configuring the encapsulation type and trunking status. By functioning at Layer 2, DTP can utilize the capabilities of MAC addresses to identify devices on the same local area network (LAN), facilitating the establishment of trunk links without requiring manual configuration from network administrators. This ability to dynamically manage trunk settings enhances network flexibility and scalability, making it easier to implement VLANs and maintain efficient network operations.