Which command-line utility is used on Linux to monitor traffic from the network?

• A. Tcpdump
• B. Ifconfig
• C. Top
• D. Ls

Answer: (A)

Capturing and inspecting network packets is the goal when monitoring traffic on a Linux system. The tool that fits this purpose best is tcpdump. It’s a command-line packet analyzer that captures live traffic from a network interface and prints a readable representation of each packet, with powerful options to filter exactly what you want to see (for example, by protocol, port, or IP address). You can also save captures to a file for later analysis with tools like Wireshark. Running something like sudo tcpdump -i eth0 shows real-time traffic on that interface, and you can add filters such as port 80 to focus on HTTP traffic.

Ifconfig is used to configure and display network interfaces, not to monitor ongoing traffic. Top shows running processes and system resource usage, not network packets. Ls lists files and directories, which is unrelated to network monitoring.