10 Excellent Linux Network Monitoring Tools

Effective network management is essential for preventing programs from monopolizing bandwidth and slowing down a system. For administrators who prefer working from the terminal—especially over SSH—this guide presents ten Linux network‑monitoring tools that run without a graphical interface.

1. iftop

iftop is similar to top but focuses on network traffic. It shows real‑time bandwidth usage per process, allowing users to see which applications are consuming network resources.

2. vnstat

vnstat is included in most Linux distributions by default. It records the amount of data sent and received over user‑specified time intervals, providing real‑time traffic statistics.

3. iptraf

iptraf is a console‑based real‑time network monitor that gathers detailed IP traffic information, including TCP flags, ICMP details, TCP/UDP flow errors, and per‑interface statistics such as checksum errors and activity.

4. Monitorix

Monitorix is a lightweight, free application that monitors a wide range of Linux/Unix system and network resources. It includes an embedded HTTP server that collects data periodically and displays it in charts, covering load average, memory, disk health, services, network ports, mail statistics, MySQL stats, and more. It helps detect faults, bottlenecks, and abnormal activity.

5. dstat

dstat is a lesser‑known tool that is included by default in some distributions. It provides a versatile view of system resources and can be useful when other tools are unavailable.

6. bwm‑ng

bwm‑ng is one of the most minimalistic tools. It interactively gathers bandwidth data from interfaces and can export the information in various formats for use by other devices.

7. ibmonitor

ibmonitor displays filtered network traffic per interface and clearly separates inbound from outbound traffic.

8. htop

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

9. arpwatch

arpwatch monitors Ethernet traffic, recording IP‑to‑MAC address mappings with timestamps. When a new or changed mapping is detected, it can email the system administrator—useful for detecting ARP attacks.

10. Wireshark

Wireshark is a free, open‑source packet analyzer that captures and inspects traffic flowing to and from the system. It can drill down to individual packets, making it valuable for protocol analysis and testing. Originally named Ethereal, Wireshark is widely regarded as the de‑facto standard for network analysis.

Conclusion: The article presents a selection of open‑source network monitoring tools, noting that while these are considered “best” for many scenarios, they may not suit every need. Other solutions such as OpenNMS, Cacti, and Zabbix exist, and users should evaluate each tool’s strengths against their specific requirements. Proprietary alternatives are also available.