In 2015, we reviewed the top must-have free networking tools. And honestly, these reviews have stood the test of time. But now that time has passed, the landscape has changed and we think it's worth revisiting these old options and possibly adding some new ones.
laying the foundation
To build a network, you start with an architecture, design the layout, analyze and choose the hardware that meets your requirements. Because many organizations need their network up and running to generate revenue, it's critical to have the right set of tools to monitor and manage the one you've lovingly created.
But how do you find the best network monitoring tools when there are hundreds of commercial products, free tools and open source software to choose from? While the free versus commercial debate continues, it has been tried and tested,free network monitoring toolstrusted by many network administrators. Below, we'll share some of our favorites with you.
Open source options are good and can even combine with commercial tools, but you should be aware that using open source monitoring requires a high level of engagement with the tool, which may not perfectly suit your needs. As the saying goes, "Open source is only free if your time isn't worth it."
Open source monitoring solutions often require a significant investment in time and resources. Missing features may need to be created with help from community support or an internal IT team. The second consideration is security, which can become an issue depending on the tool selected and your company's security guidelines. Also, out-of-the-box custom fixes may not be available unless you spend time developing and maintaining them yourself.
If you are looking for a robust and affordable network monitoring tool that offers a greater degree of automation and insight and a lower degree of manual input required than an open source solution,solar winds®ipMonitor®may be a good option for you. ipMonitor offers scalable network monitoring for your entire network in a fast, lightweight and easy-to-use solution designed to help minimize downtime and the time required to manually monitor your network.
The tool's getting started wizard guides you through the automated processes of discovering and setting up alerts so you can start gaining insights into your network quickly. ipMonitor even offers out-of-the-box recommendations on what to monitor in each of your apps and devices.
One reason why someone might want to use a free network monitoring solution is because they are intimidated by a paid solution. In fact, paid network monitoring tools are often much easier to use than their free counterparts. That's certainly true when it comes to ipMonitor, as the easy-to-use interface helps you quickly identify current (and even potential) issues so you can get to the bottom of them before they cause even more problems for your network's performance. ipMonitor helps ensure you never miss a thing with its powerful configurable alert system. With over a dozen different notification types built in, ipMonitor helps you ensure the right people on your team are aware of potential issues as soon as the tool detects them.
ipMonitor is an affordable option for businesses of any size, but if you're not sure you want to commit to a paid tool, give one a try.14 days free trialto see if the tool is suitable for your needs.
When we need a network monitoring tool that is easy to install and supports out-of-the-box monitoring and reporting, we like it.solar winds®Network Performance Monitor (NPM). NPM acts as a one-stop shop to provide complete and comprehensive network monitoring features that complement some of the essential free tools you may already be using.
As business networks are becoming larger and more complex, it is important to placenetwork monitoring and management solutionsat the beginning of the implementation phase.
What's on the list?
If youto doIf you decide to go the open source/free route, please check the following. It's our list of the best free network monitoring tools available today.
núcleo do nagios
nagios®is the great-grandfather of monitoring tools, and only ping is more ubiquitous in some circles.
Nagios is popular due to its active development community and its compatibility with external plugins. You can create and use external plugins in the form of executable or Perl files®and shell scripts to monitor and collect metrics for every piece of hardware and software used on a network. There are plugins that provide a better and easier GUI, they address many limitations in Core®and supporting features such as automatic discovery, extended charts,notification escalation, youadvance.
cactus®It's another one of the monitoring workhorses that remains an option for network monitoring needs. It lets you collect data from almost anything on the network, including routing and switching systems as well as firewalls, and put that data into robust graphs. If you have a device, Cacti's active developer community may have created a monitoring template for it.
Cacti supports SNMP polling, which in turn covers a wide range of network devices. You can also extend Cacti's capabilities to use scripts, queries or commands to collect data and save them as a template to use to search other devices for similar datasets. Cactus harnesses the power ofDRR tool, an open source data logging and graphing system for creating graphs from stored datasets. RRDTool data consolidation allows you to store the collected data forever and is only limited by the size of your storage. Cacti also lets you add multiple users and grant them access with or without edit permissions, which is perfect for service providers and companies with a large NOC team.
It is true that complex to configure, Zabbix®It comes with a simple and clean graphical user interface that makes it easy to manage once you get the hang of it. Zabbix supports agentless monitoring using technologies like SNMP, ICMP, Telnet, SSH, etc., and agent-based monitoring for all Linux®distributions, windows®SO and Solaris®. It is compatible with several databases including MySQL®,postgresql™,SQLite,Oracle®, youIBM®DB2®. VMware the ZabbixName®monitoring features allow you to customize using any script or programming language, which is widely considered its best feature.
Zabbix is probably the most used open source network monitoring tool after Nagios.
ntop, which is now ntopng (ng forNext generation), is a traffic probe that usesbook cover(for packet capture) to report network traffic. You can install ntopng on aserverwith multiple interfaces and use port mirroring or network tapping to feed ntopng packets of network data for analysis. ntopng can analyze traffic even at 10G speeds; report on IP addresses, volume and bytes for each transaction; classify traffic based on IP, port and protocol; generate usage reports; see keynote speakers; and report the AS information. This level of traffic analysis helps you make informed decisions about capacity planning and QoS design, and helps you find bandwidth-hungry users and applications. ntopng has a commercial version called ntopng pro that comes with some extra features, but the open source version is good enough to get information about traffic behavior quickly. ntop can also integrate with external monitoring applications such as Nagios to alert and provide data for monitoring.
ntopng has some limitations, but the level of network traffic visibility it provides is well worth the effort.
Built on top of MySQL and PostgreSQL, Icinga is backwards compatible with Nagios, which means that if you invest in Nagios scripts, you can port them over with relative ease.
Icinga was created in 2009 by the same group of developers that created Nagios, so they knew what they were doing. Since then, the developers have made great strides in terms of expanding functionality and usability since then. As Nagios' pedigree might suggest, its primary focus is monitoring infrastructure and services.
Spiceworks offers many free IT management tools, including inventory management, help desk workflow, and even cloud monitoring, in addition to the network monitoring solution I'm focusing on here. Based on agentless techniques such as WMI (for Windows machines) and SNMP (for networks and *nix systems), this free tool can provide insight into many network performance issues. You can also set customizable notifications and restart services from within the app.
Remember that Spiceworks is free because most of its revenue comes from selling ads on its network. It's a small price to pay for a free solution, but something to think about before installing.
Observium follows the "freemium" model that most of the open source community now adopts: a core set of free features, with additional options if you pay for them. While the "community" (i.e. free) version supports an unlimited number of devices, Observium is still careful to say that it's designed for home lab use. This is reinforced by the fact that the free version cannot scale beyond a single server. Run this on your corporate network at your own risk!
The free version also has a 6 month patch and update cycle. If you want fixes faster than twice a year, you'll have to pay for them. One of the most painful features held back from the free version is its lack of alert features. These caveats aside, you get full automatic discovery of your devices and metrics (using SNMP and standard protocols as usual).
Top related tools for network monitoring
There are some tools that are not monitoring solutions per se, but are so incredibly useful for the monitoring professional that we don't think it's right to leave them out.
wire shark®is an open source packet sniffer that uses libpcap (*nix) or winpcap (Windows) to capture packets and display them in its graphical interface, while providing good filtering, grouping, and analysis capabilities. It allows users to capture wire-speed traffic or read packet dumps and analyze details at microscopic levels. Wireshark supports almost all protocols and has features that filter based on packet type, source, destination, etc. You can analyze VoIP calls, plot I/O graphs for all traffic on an interface, decrypt many protocols, export output, and much more.
Wireshark offers unlimited opportunities to study packets, making it a solid resource for network, system, and security administrators.
Nmap uses a discovery feature to find hosts on the network which can be used to create a network map. Network administrators value it for its ability to collect host information about the operating system, running or open services or ports, MAC address information, reverse DNS name, and much more.
Scalability is the other big reason why network administrators love Nmap. You can scan a single host or an entire network with "hundreds of thousands" of machines.
When you need to quickly map the hosts on your network, Nmap is your tool.
Free network monitoring tools
Most of the tools we've focused on in this post are of the "freemium" variety: a limited set of features (or support) for free, with additional features, support, or offerings available for a cost.
But there is another class of tools that are simply free. They perform a specific task very well and are free (with the exception of the occasional popup during installation). We wanted to take a moment to delve into some of the tools found in the "network_utilities" directories on our systems that are used frequently.
Furthermore, we want to make it clear that the list below is not intended to be (or appear to be) exhaustive. There are many, MANY useful free network monitoring tools out there, and which ones an IT professional uses often depends on personal preference or the specifics of their work environment. We've listed the ones we've come across on our travels and the ones we use frequently.
trace route from
The ping is great. Traceroute is better. But both fall short with modern networks (and especially with Internet-based targets because the Internet is inherently multipath). A pack has multiple ways to hit a target at any given time. You don't need to know how a SINGLE packet got to its destination; you need to know how ALL packets move across the network over time. Traceroute NG does this and avoids the biggest obstacle to ping and traceroute accuracy (ICMP suppression) at the same time.
If you are doing simple monitoring, the first question you should ask is "is it working?" Right after, "how much bandwidth are you using?" Yes, it's a simplistic question and an answer that might not really point to a problem (because let's be honest, a circuit that is 98% utilized most of the time is called "correctly provisioned" in our book), but that doesn't means means you don't want to know. This tool gets this information quickly, easily and shows the results clearly.
Response Time Visualizer for Wireshark
We mentioned Wireshark in the unmonitored monitoring tools section because of its flexibility, usefulness, and ubiquity. But the "age" that was left out was "simplicity". This sucker can be difficult to learn to use, especially for new network engineers just at work. This utility will take Wireshark data and analyze it to display some important statistics simply and clearly. Specifically, it collects, compares, and displays the time for a triple handshake versus the time for the first byte between two systems. Effectively, it shows whether a perceived slowdown is due to the network (three-way handshake) or application response (time to first byte). This can be an effective way to reduce troubleshooting work and focus on solving the right problem more quickly.
IP SLA monitoring
The IP SLA is one of the most overlooked techniques in a monitoring specialist's arsenal. Relegated to being “that protocol for VoIP”, the reality is that IP SLA operations can bring much more than jitter, packet loss and MOS. You can test a remote DHCP server to see if it has addresses to deliver, check the DNS response from anywhere in your enterprise, verify that essential services like FTP and HTTP are running, and much more.
Therefore, this free tool is a kind of secret weapon for engineers who need to perform miraculous tasks on the cheap.
What have we learned?
This year, monitoring professionals have almost an embarrassment of riches when it comes to free and open source solutions to help us get our jobs done. While none of these free tools are exactly easy to set up, maintain, or use, if your tool budget is close to zero and you have the time to invest, they might meet your needs. Otherwise, we recommend using a tool likeNPM solar winds, which is easy to install and supports movement and reporting right out of the box.