Which of the following is a common symptom of network congestion?

Network congestion occurs when the demand for network resources exceeds the available capacity, leading to various performance issues. One common symptom of network congestion is latency spikes. When congestion occurs, packets of data can become delayed as they queue up for processing and transmission. This delay results in increased latency, which can significantly affect the responsiveness of applications and services relying on the network.

In contrast, increased throughput typically indicates an efficient flow of data, which is not the case during congestion. Similarly, reduced firewall activity would imply less processing and monitoring, which doesn't relate to network congestion symptoms. Enhanced data integrity suggests that data is being transmitted without errors, but during congestion, there is often an increased likelihood of packet loss and errors, not enhancement. Therefore, latency spikes serve as a clear and direct indicator of network congestion issues.