Network Monitoring Tools You Have To Know

We all understand how system administrators love to have network monitoring tools which make their lives easier. Following is a list of the best tools for monitoring devices, ports or protocols, services, and for analyzing traffic on the network. Even if the administrator may have used some of these tools before, I’m sure he will find at least a gem or two amongst this tools list.

GFI LanGuard

This tool is a complete vulnerability management solution that allows system administrators to scan, assess, detect, and rectify the security vulnerabilities on their network. GFI LanGuard provides the appropriate tools to remediate the vulnerabilities and to install the missing patches on the network. This tools also gives the system administrator a complete picture of his network set-up and helps him to maintain a secure network state more effectively and faster.


This tool is an open source enterprise grade network management app, which offers an automated discovery, performance measurement, event and notification management, and also service assurance features. OpenNMS tool includes a client application for iPod Touch, iPhone, or iPad for “on-the-go access” which gives the system administrator the ability to view nodes, outages, alarms and also add a specific interface for monitoring.

Check the following article to know how to install OpenNMS in Ubuntu.


This is a web debugging tool which captures the HTTP traffic between selected computers and the Internet. Fiddler allows the system administrators to analyze outgoing and incoming data in order to modify and monitor responses and requests just before they hit the browser. This tool also gives system administrators an extremely detailed information about the HTTP traffic and may be also used for testing their websites’ performance or their web applications’ security testing (For instance, Fiddler can simply decrypt HTTPS traffic).


Ganglia is simply a scalable distributed network monitoring solution which is focused on grids and clusters. It gives system administrators an easy-to-read and quick overview of their entire clustered system. This tools can scale in order to handle clusters with up to 2,000 nodes. Ganglia has been ported to various platforms and is also used on thousands of clusters worldwide. Any system administrator who employs server clusters should have this tool in order to monitor that system.

Check the following article to know how to install Ganglia in Debian and Ubuntu.


Our tools list couldn’t be complete without WireShark. This tool is simply a capture utility and an interactive network protocol analyzer. WireShark provides for in-depth inspection of 100s of protocols and also runs on multiple platforms.

Pandora FMS

This tool is a network monitoring, performance monitoring, and also availability management tool which keeps an eye on applications, servers, and communications too. Pandora FMS has an advanced event correlation system which can allow the system administrator to create alerts according to events from various sources and then notify administrators before any issue escalates.

Check the following links to install Pandora FMS in CentOS.

Microsoft Network Monitor

This is another network monitoring tool and is a packet analyzer which allows system administrators to view, capture, and analyze their network traffic. This handy tool is the best option for troubleshooting their network problems and/or applications on their network. The main features of this tool include simultaneous capture sessions, support for over 300 Microsoft proprietary and public protocols, Wireless Monitor Mode, and also sniffing of the promiscuous mode traffic.

Advanced IP Scanner

This small tool is easy to use and fast network scanner which detects any kind of network devices such as wireless devices including printers, mobile phones, and also WIFI routers on the network. Advanced IP Scanner allows system administrators to connect to the common services including HTTP, FTP, and also shared folders in case if they are enabled on the remote machine. System admin is also able to wake up and shut down remote computers anytime.


This tool is as powerful as all other network monitoring tools, as it offers mapping on its Web-based console, user-defined views, and zooming. It also collects nearly ANY kind of data you want to monitor, offers an agent-less monitoring, can monitor up to 10,000 devices, and it does the availability and SLA reporting. The administrator can also get commercial support for this outstanding product. A unique Zabbix feature is an option to set the audible alerts.

Check the following links to install Zabbix on CentOS and Ubuntu.


This tool is able to capture network packets and then parse data in order to extract files and images which help system administrators to reconstruct events which users have taken on the network. NetworkMiner can also do that by simply parsing the pre-captured PCAP file. The system administrator can enter keywords that will be highlighted as the network packets are captured. This tool is classed as NFAT (Network Forensic Analysis Tool) which can obtain information including operating system, hostname, and open ports from the hosts.

PRTG Network Monitor Freeware

This network monitoring tool can monitor the network availability and usage by using different protocols such as Netflow, SNMP, and WMI. PRTG Network Monitor is a powerful tool which offers an easy to use web-based interface and applications for Android and iOS. Amongst other network tools, this tool’s key features include:

  • Flexible Alerting: It has 9 different methods for notifications, conditional alerts, limit alerts, status alerts, threshold alerts, and alert scheduling.
  • Comprehensive Network Monitoring: This offers about 170 sensor types or even more for application monitoring, SLA monitoring, virtual server monitoring, and QoS monitoring.
  • In-Depth Reporting: This includes the ability of scheduling reports, creating reports in HTML/PDF format, as well as the pre-defined reports and report templates.


This tool is considered by thousands of system administrators as the king of the open source network monitoring solutions. But at the same time it isn’t the easiest tool to set up or to configure as you must edit configuration files manually. The idea behind the manual configuration is to turn some features off, which actually makes this tool one of the most flexible network monitors ever.

Check the following links to install nagios on CentOS and Ubuntu.

Capsa Free

This tool is a network analyzer which allows system administrators to troubleshoot network issues, monitor network traffic, and analyze packets. Features of this tool include MSN and Yahoo Messenger filters, support for over 300 network protocols, auto-save, email monitoring, ability to create and customize protocols, and customizable dashboards and reports.

Zenoss Core

Another powerful open source IT monitoring platform which can monitor servers, networking, applications, storage, and virtualization in order to provide performance statistics and availability. The tool has also high-performance event handling system as well as an advanced notification system.

The Dude

This friendly tool is another network monitoring tool which can monitor alerts you when there is any problem with devices. The tool automatically scans all the devices on a chosen subnet and then layout and draw maps of your network.

Angry IP Scanner

This standalone application can facilitate the IP address and port scanning. Angry IP Scanner is used for scanning a range of IP addresses in order to find hosts which are alive and obtain information about them such as open ports, MAC address, hostname, NetBIOS information, ping time, etc.

Check the following link to install Angry IP Scanner in CentOS and Ubuntu.

Total Network Monitor

This tool can continuously monitor services and hosts on the local network, and then notify you of any issue which requires your attention via a very detailed report of the problem. The result of each probe can be classified using red, green, or black colors in order to quickly show whether that probe was successful, wasn’t able to complete, or had a negative result.


This is a web-based system which is designed to run on Unix-based systems, allowing you to dive deeper into performance, configurations, and real-time statistics of the networking environment. The tool also offers monitoring capabilities with reporting, performance graphs, and historical data.

Xirrus Wi-Fi Inspector

From its name, you can understand that this tool can be used to search for Wi-Fi networks, locate Wi-Fi devices, verify Wi-Fi coverage, manage and troubleshoot connections, and also detect rogue Access Points. Xirrus Wi-Fi Inspector usually comes with built-in speed tests, quality, and connection.


This can be considered as data analysis and collection platform which will allow the system administrator to monitor, gather, and analyze data from various sources on the network such as TCP/UDP traffic, devices, event logs, services, etc. The system administrator can set up alerts to be notified when something went wrong or he can use Splunk’s reporting, extensive search, and dashboard features in order to make the most of those collected data. This platform will also allow him to install ‘Apps’ in order to extend system functionality.

Icinga 2

This application is another Linux based fully open source network monitoring application that will check the availability of network resources and can immediately notify users when something is down. The application also provides a powerful command line interface, BI (business intelligence) data for in-depth analysis.

Check the following article to install Icinga 2.


This is a lightweight utility, which is available as an installation package or as a standalone executable, which will monitor the activity of the reachable wireless networks and then it will display information related to them including Signal Quality, SSID, Channel Number, MAC Address, Cipher Algorithm, etc.


Spiceworks is a fast growing tool which becomes one of the industry standard free system/network monitoring tools. Although, as it is a free tool, it comes with some ads, its features, and its Web-based interface can’t be beaten comparing to other tools. This outstanding tool will monitor and auto-discover all your systems, offer outstanding topographical tools, and will alert you in case if something is down. Spiceworks also allows system administrators to get social with fellow IT pros through the Spiceworks community that is now built right in.

I’m pretty sure that every reader at least used, or is using, at least one on these outstanding free network monitoring tools. If you think that I didn’t cover all available tools that are rated by thousands of system administrators all over the world and other simple users, then comment down please your tool and tell us why you prefer to use it not what I listed above.