The #netstat -an command output typically displays a list of all open ports and associated connections. If the web application is slowed down, the engineer would look for unusual patterns such as an excessive number of connections to the web server which could indicate a denial-of-service attack. However, without specific details from the #netstat -an output, it's not possible to determine the exact cause of the issue. Therefore, the engineer would need to gather more data, possibly including checking server logs, resource usage, and network traffic patterns to diagnose the problem accurately.
References: Understanding Cisco Cybersecurity Operations Fundamentals (CBROPS) provides knowledge on network monitoring tools and interpreting their output to identify potential security incidents.