JNCIS-ENT: Juniper Networks Certified Specialist – Enterprise Routing and Switching (2025) — Question 33

Which two mechanisms are part of building and maintaining a Layer 2 bridge table? (Choose two.)

Answer options

• A. blocking
• B. flooding
• C. learning
• D. listening

Correct answer: B, C

Explanation

The correct answers are flooding and learning. Flooding is used to send frames to all ports in the network when the destination MAC address is unknown, while learning allows the bridge to build its MAC address table by identifying the source MAC addresses of incoming frames. Blocking and listening are not mechanisms for building or maintaining the bridge table; blocking prevents certain traffic, and listening is a state where the bridge does not forward frames.