Cisco Certified Network Professional Practice Test 2026 – Your All-in-One Guide to Exam Success!

The correct answer indicates that the aging time for the bridge table is set to 15 seconds in the event of a topology change. This is mainly due to the need for rapid convergence and updated information within the network when changes occur. When there is a topology change, the network needs to ensure that any outdated or incorrect MAC address entries are removed quickly, which is crucial for maintaining the efficiency and accuracy of forwarding decisions.

By setting the aging time to a relatively short duration of 15 seconds, the network can clear out stale entries promptly, allowing new entries to be added based on the current topology. This helps in adapting quickly to any changes, such as new devices being added or existing devices being removed.

In contrast, other options either suggest longer aging times or a status that remains unchanged, which would not support the rapid adjustments necessary in a dynamically changing network environment. Therefore, establishing an aging time of 15 seconds reflects the need for agility in handling MAC address information effectively within the context of network topology changes.