Cisco Certified Network Associate (CCNA) Practice Exam

What does Uplink Fast do in a network?

1. It improves the speed of VLAN convergences.

2. It marks redundant links towards the root bridge as alternate ports.

3. It disables all redundant links.

4. It provides backups for all assigned ports.

The correct answer is: It marks redundant links towards the root bridge as alternate ports.

Uplink Fast plays a significant role in enhancing the efficiency of Rapid Spanning Tree Protocol (RSTP) by ensuring a quicker transition of blocked ports to a forwarding state under certain conditions. Specifically, when a failure occurs in the primary link to the root bridge, Uplink Fast allows a switch to quickly activate a redundant link that has been previously designated as alternate. By marking these redundant links towards the root bridge as alternate ports, Uplink Fast reduces the time it takes for the network to re-establish connectivity, ultimately leading to a more resilient and responsive network infrastructure. This mechanism allows for faster convergence times, which is critical in maintaining network performance, especially in environments where downtime can impact operations significantly. In contrast, improving the speed of VLAN convergences is not directly addressed by Uplink Fast, nor does it disable all redundant links or provide backups for all assigned ports. Instead, it specifically focuses on efficiently managing redundant links to optimize network reliability.