10 Must‑Try Linux Network Monitoring Tools

Maintaining control over network usage is crucial for administrators to prevent programs from overwhelming bandwidth and slowing the system. The following ten command‑line tools run on Linux and are ideal for users who manage networks via SSH without a GUI.

1. iftop

Similar to top, iftop focuses on network traffic, showing detailed per‑process usage and real‑time bandwidth consumption.

2. vnstat

vnstat is included by default in most Linux distributions. It records sent and received traffic over a user‑selected time period, providing real‑time control of bandwidth usage.

3. iptraf

iptraf is a console‑based real‑time network monitor that gathers a wide range of information, including TCP flags, ICMP details, TCP/UDP traffic errors, packet and byte counts, and interface activity.

4. Monitorix

Monitorix is a lightweight, free application designed to monitor many system and network resources on Linux/Unix servers. It includes an embedded HTTP server that periodically gathers data and displays it in charts, tracking load, memory, disk health, services, network ports, mail statistics, MySQL stats, and more, helping detect faults, bottlenecks, and abnormal activity.

5. dstat

dstat is a less‑known but often pre‑installed tool that provides a concise, real‑time view of various system statistics, including network I/O, and can export data in several formats for further processing.

6. bwm‑ng

bwm‑ng is a very lightweight tool that interactively displays bandwidth usage per interface, separating inbound and outbound traffic and offering export options for other devices.

7. ibmonitor

ibmonitor shows filtered network traffic on each interface, clearly distinguishing received from transmitted data.

8. htop

htop is an advanced, interactive, real‑time process viewer similar to top but with a more user‑friendly interface, shortcuts, and both horizontal and vertical process views. It is not included by default and must be installed via package managers such as yum or apt‑get.

9. arpwatch

arpwatch monitors Ethernet activity, logging IP and MAC address changes with timestamps. It can email administrators when a new or changed address pair appears, which is useful for detecting ARP attacks.

10. Wireshark

Wireshark (formerly Ethereal) is a free, open‑source packet analyzer that captures and inspects traffic flowing to and from the system. It provides deep packet inspection, protocol analysis, and is widely regarded as the industry standard for network troubleshooting.

Conclusion

The article examined several open‑source network monitoring utilities and selected those considered “best” for typical Linux environments. However, the optimal tool depends on individual requirements; alternatives such as OpenNMS, Cacti, Zennos, or proprietary solutions may be more suitable in specific scenarios.