CCNA Routing and Switching (legacy) — Question 181

Which are valid modes for a switch port used as a VLAN trunk? (Choose three.)

Answer options

• A. transparent
• B. auto
• C. on
• D. desirable
• E. blocking
• F. forwarding BCD

Correct answer:

Explanation

The correct modes for a VLAN trunk port are 'on', 'desirable', and 'auto'. 'On' forces the port to trunk, 'desirable' actively tries to negotiate a trunk with the connected device, and 'auto' allows the port to become a trunk if requested. The other options either do not apply to trunking or represent incorrect modes for this function.