Cisco Certified Network Associate (CCNA) Practice Exam

What does Trunk mode of Dynamic Trunking Protocol do?

1. Terminates the trunking session

2. Disables trunking on the interface

3. Enables trunking on the interface

4. Configures VLANs on the interface

The correct answer is: Enables trunking on the interface

The trunk mode of Dynamic Trunking Protocol (DTP) is indeed responsible for enabling trunking on the interface. In a networking context, trunking allows multiple VLANs (Virtual Local Area Networks) to be carried over a single physical link between switches. By enabling trunking, the switch can communicate multiple VLANs across that link, as the trunking protocol dynamically negotiates the trunking mode between two devices. When an interface is configured to trunk mode, it allows for the passage of traffic from multiple VLANs, which is essential for ensuring that VLAN segregation is maintained across different segments of a network. This capability is particularly important in larger networks where keeping VLAN traffic isolated enhances performance and security. Others options relate to different functionalities: terminating a trunking session would mean stopping trunk communication, disabling trunking would restrict the interface to a single VLAN, and configuring VLANs on the interface does not inherently involve trunking—it simply defines what VLANs are present on that interface.