CCIE Service Provider (legacy) — Question 14

An IEEE 802.1ad deployments, which three represent valid port models? (Choose three.)

Answer options

• A. UNI S-port
• B. NNI C-port
• C. NNI S-port
• D. UNI T-port
• E. UNI C-port
• F. NNI

Correct answer: A, E, F

Explanation

The valid port models for IEEE 802.1ad are UNI S-port, UNI C-port, and NNI. The UNI S-port connects user equipment to the network, while the UNI C-port is a customer-facing port. NNI represents a network-to-network interface, which is also valid. The other options, such as NNI C-port and NNI S-port, do not conform to the 802.1ad standard requirements.