Designing Cisco Network Service Architectures (ARCH, legacy) — Question 72

In what situation must spanning-tree be implemented?

Answer options

• A. when fast convergence is required for link failures
• B. when redundant Layer 2 links, that are not part of a single EtherChannel or bundle, exist between distribution switches
• C. when trunks need to extend multiple VLANs across access switches
• D. when a VLAN spans access layer switches

Correct answer: B

Explanation

The correct answer is B because spanning-tree is essential to prevent loops in a network with redundant Layer 2 links that are not aggregated. Option A is incorrect as fast convergence pertains to rapid recovery rather than the necessity of spanning-tree itself. Options C and D do not specifically address scenarios that require spanning-tree implementation for loop prevention.