80+ Essential Linux Monitoring Tools Every Sysadmin Should Know

As the internet industry evolves, countless monitoring tools have emerged. This article compiles the most complete list of Linux monitoring utilities, offering more than 80 ways to manage your machines.

Command‑line tools

Network‑related tools

System monitoring tools

Log monitoring tools

Infrastructure monitoring tools

Eight System Monitoring Tools

1. top

top is a small utility pre‑installed on many UNIX systems. It provides a real‑time view of running processes or threads, sorting them by CPU usage by default.

2. htop

htop is an enhanced version of top, offering easier process sorting, a more intuitive interface, many built‑in operations, and full interactivity.

3. atop

atop is similar to top/htop but can log process information daily for later analysis, highlight resources that have reached critical load, and display resource consumption for all processes.

4. apachetop

apachetop monitors the overall performance of the Apache web server, showing the number of read, write, and request processes.

5. ftptop

ftptop provides basic information about all connections to an FTP server, such as total sessions, active uploads/downloads, and client identities.

6. mytop

mytop is a lightweight tool for monitoring MySQL threads and performance, allowing you to view the database and active queries in real time.

7. powertop

powertop helps diagnose power‑consumption and power‑management issues, offering configuration options to optimize server power usage; navigation is done with the Tab key.

8. iotop

iotop checks I/O usage and provides a top‑like interface displaying read/write rates per process, showing the percentage of time each process spends waiting for I/O.

Network‑Related Monitoring Tools

9. ntopng

ntopng is an upgraded version of ntop, offering a web‑based graphical UI for network monitoring, host geolocation, traffic visualization, and IP flow analysis.

10. iftop

iftop works like top but focuses on network interface traffic, displaying current usage in a table and answering questions such as “Why is my network slow?”

11. jnettop

jnettop visualizes network traffic similarly to iftop but with richer graphics, supports custom text output, and provides an interactive deep‑analysis of logs.

12. bandwidthd

BandwidthD tracks TCP/IP subnet usage and visualizes it in a browser via PNG images, offering a database for searching, filtering, multi‑sensor support, and custom reports.

13. EtherApe

EtherApe graphically displays network traffic, supporting many nodes, capturing real‑time data, reading from tcpdump, and applying pcap filters to show specific information.

14. ethtool

ethtool displays and modifies parameters of network interface controllers, assists in diagnosing Ethernet devices, and provides detailed statistics.

15. NetHogs

NetHogs groups network traffic by process rather than by protocol or subnet, making it easy to identify which process is causing a traffic spike.

16. iptraf

iptraf collects various metrics such as TCP connection packets/bytes, port statistics, activity indicators, and TCP/UDP communication failures.

17. ngrep

ngrep is “network grep”; it uses pcap to match packets against extended regular expressions or hexadecimal patterns.

18. MRTG

MRTG was originally developed to monitor router traffic but now can monitor various network resources, collecting data every five minutes and generating HTML pages with optional email alerts.

19. bmon

bmon monitors and helps debug network performance, capturing statistics and presenting them in a friendly UI; it can also be scripted for automation.

20. traceroute

traceroute is a built‑in tool that displays the route and measures packet latency across the network.

21. IPTState

IPTState lets you observe how traffic traverses iptables, sort it by custom conditions, and delete state entries from iptables tables.

22. darkstat

darkstat captures network traffic, computes usage statistics, and serves a simple HTTP interface with a graphical UI for analysis.

23. vnStat

vnStat is a low‑resource network traffic monitor that relies on kernel‑provided statistics; data persists across reboots and includes color options for visual appeal.

24. netstat

netstat is a built‑in tool that shows TCP connections, routing tables, and network interface statistics, useful for troubleshooting network issues.

25. ss

Compared with netstat, ss -s provides more detailed and faster output of socket statistics.

26. nmap

Nmap scans open ports on a server, detects the operating system, and can be used for SQL injection detection, network discovery, and penetration testing.

27. MTR

MTR combines traceroute and ping, limiting hop count per packet, monitoring arrival, and repeating the test each second.

28. tcpdump

tcpdump outputs information about captured packets that match the expression you specify on the command line; results can be saved for further analysis.

29. Justniffer

Justniffer is a TCP packet sniffer that lets you collect low‑level or high‑level data and generate custom logs, e.g., mimicking Apache access logs.