Network tools have evolved a lot since their inception some thirty years ago. They are now more flexible and easy to set up than ever. Not every administrator like them but all agree–sometimes unwillingly–that they are necessary, even though they can be viewed by some as a necessary evil. We’re using the term monitoring tool loosely as a generic term to describe several different types of tools. All have one thing in common, though, they’re used to monitor some normally hidden parameter of our networks.
Before we dive into the core of our subject, we’ll briefly pause to discuss network monitoring tools in general. We’ll explain why you need to use them and what types of tools there are out there. As you’ll see, there are different types of tools for different purposes. And once we’re all on the same page, we’ll reveal our 12 best network monitoring tools, briefly reviewing each one.
Why Use Network Monitoring Tools
There’s a very simple reason why anyone would want to use network monitoring tools. More than anything, it has to do with the fact that we normally can’t see what’s going on inside the network. We’ve all seen networks compared to highways and data packets compared to cars using those highways. But there’s a big difference. The traffic on a highway is visible. You just have to look and you’ll see whether or not there’s congestion.
It’s not so simple with networks. Everything happens at the molecular level inside copper wires or optical fibers. And even if we could see the traffic going by, it is so fast that we wouldn’t be able to make any sense of it. Monitoring tools allow us to visualize the traffic and load levels of wired and wireless networks. Some of them are intended as surveillance tools while others are troubleshooting tools or even forensic investigation tools.
Different Tools For Different Tasks
Network monitoring tools fall mainly into three categories. There are bandwidth usage monitor, network analyzers, and packet sniffers. There also other types of tools as well as tools that are hybrids of several types but their number is limited. The one you’ll choose depends on your expected results. Each type of tool will be best suited for a specific task.
Bandwidth monitors use the SNMP protocol to poll networking devices and read their interfaces’ traffic counters. They use these numbers to compute bandwidth usage by unit of time–usually in bits per second or bps–and display it on a graph showing its evolution over time. They are typically used for capacity monitoring and planning. They will let administrators see the evolution of bandwidth usage and proactively plan the upgrade of overutilized circuits.
Network analyzers go a bit deeper and take advantage of the NetFlow feature of many networking equipment. NetFlow–which also goes by other names depending on the manufacturer–collects detailed data about each conversation a device handles and sends it to a flow collector and analyzer. The collected information can include source and destination addresses and ports, type of traffic, QoS parameters, and several more element that allow the analyzer to not only know how much data is transferred but also what data is transferred. It is, for example, very useful in pinpointing bandwidth hogs or identifying unwanted traffic on a network.
Packet sniffers are some of the deepest monitoring tools. As their name implies, they connect to a network where they capture every data packet going by. But they don’t only capture them. They also decode them and display their headers and sometimes even the data payload when it’s not encrypted. Their strength and usefulness come mainly from their ability to filter captured data according to several criteria, letting users zero in on precisely the data that interests them. They are typically used for advanced debugging such as when you’re trying to figure what is slowing down a specific server or service. Those are complex and highly specialized tools that typically go well beyond monitoring so we’re not including any such tools on our list.
Our Top 12 Best Network Monitoring Tools
Our list of the 12 best network monitoring tools includes mostly SNMP bandwidth monitors as they are arguably the most useful. We’re also including other types of tools such as flow analyzers and up or down monitors.
The SolarWinds Network Performance Monitor, or NPM, is Solarwind’s flagship product. It is possibly one of the best SNMP bandwidth monitoring tools. It is packed with so many features that a whole article could be written about it. Among the product’s main advantages, its simplicity has to be emphasized. But we don’t mean simple as in incomplete but as easy. Its dashboard, views, and charts can be customized at will. It can be set up with little efforts and start monitoring within minutes. NPM is also easily scalable. It can monitor networks of almost any size.
The SolarWinds Network Performance Monitor will periodically poll your networking equipment to read their interface counters. It will then compute the bandwidth utilization and display it as graphs showing its evolution over time. Configuring the tool is easy and requires that you specify a device’s IP address and then pick which parameter you want to monitor. NPM also has many advanced features such as the possibility to built network maps and display the critical path between two devices, a handy feature when troubleshooting slowdowns.
Pricing for the Network Performance Monitor is very reasonable, starting at around $3000. A 30-day trial is available should you prefer to try the product before buying it.
Our second pick is also from SolarWinds. It makes sense as the company makes some of the best networking tools. The NetFlow Traffic Analyzer provides somewhat of a more detailed view of network traffic. Instead of showing bandwidth usage in bits per second, it goes deeper and will provide detailed information on what the observed traffic is. It can, for instance, report on what type of traffic is more prevalent or what user is using more bandwidth. Several different views are available on the tool’s dashboard such as top applications, protocols or talkers, for instance.
As one would guess from the product’s name, the NetFlow Traffic Analyser relies on the NetFlow protocol to gather detailed usage information from your network devices. Originally from Cisco, the NetFlow protocol allows devices to send detailed information about each network “conversation”, or flow, to a NetFlow collector and analyzer such as the NetFlow Traffic Analyzer. NetFlow is not limited to just Cisco devices, though. Many manufacturers include the functionality or an equivalent in their equipment. In recent years, the NetFlow protocol has been standardized as IPFIX, or IP Flow Information Exchange, by the IETF.
Like most SolarWinds tools, a free 30-day trial version can be downloaded from SolarWinds. This is a fully featured version that has no limitation but time.
The Paessler Router Traffic Grapher, or PRTG, is one of the easiest and fastest to set up. According to Paessler, you could be up and running within minutes. While this might be a slight overstatement, it is true that setting up the product is impressively fast. Part of the ease of setting up the product is its autodiscovery feature where PRTG will scan your network and automatically add the components it finds.
PRTG’s user interface–or rather user interfaces–is another one of the tool’s strength. You can choose between a native Windows console, an Ajax-Based web interface or mobile apps for Android or iOS. The mobile apps will let you scan a QR code affixed to your equipment to quickly view its status. PRTG can monitor several parameters–not just bandwidth utilization–using SNMP, WMI, NetFlow, and Sflow.
4. WhatsUp Gold
WhatsUp Gold from Ipswitch has been around for a while. The tool’s primary function is monitoring system availability rather than operational parameters. As its name implies WhatsUp Gold will tell you what’s up and what’s not. It has one of the best alerting systems and can be configured to transmit alerts using a multitude of ways including email and SMS, to name a few.
WhatsUp Gold doesn’t only monitor devices, it can also check that services are responding. For example, it will check the availability of Exchange and SQL servers, Active Directory, IIS and Apache Web services. And if your server farm is cloud-based, WhatsUp Gold will also monitor AWS or Azure installations.
Nagios is available either as a free, open-source tool that can be downloaded and used by anyone or as a commercial product called Nagios XI. As you would expect, the commercial product has more features. But even the free edition is a very potent tool. Somewhat like WhatUp Gold, Nagios’ primary–and original–purpose is up or down monitoring.
The biggest advantage of Nagios–especially the open-source version–is its community support. Several community-developed plugins, front ends, and add-ons are available directly from the Nagios website. But if you want even more functionality, you’ll go for Nagios XI. This version adds bandwidth usage monitoring and many more useful features. A free trial is available if you want to see for yourself what this tool can do for you.
Another open-source product, Zabbix offers a very polished look and feel, much like you’d expect from a commercial product. But the product doesn’t just have a good-looking web-based interface, the feature set is impressive as well. Zabbix will monitor most network-attached devices, not just networking equipment.
Zabbix uses SNMP and also IMPI for monitoring devices. You can use the tool to monitor bandwidth, device CPU and memory utilization, general device health as well as configuration changes. The alerting system in Zabbix is also impressive. It will not only send email or SMS alerts but also run local scripts. It is fully configurable as are most areas of this excellent product.
7. ManageEngine OpManager
The ManageEngine OpManager will let you monitor routers, switches, firewalls, servers, and VMs for
fault and performance. Network devices’ performance is checked in real time and can be viewed on live dashboards and graphs. Critical metrics such as packet loss, errors, and discards are monitored. The tool will also monitor your physical and virtual servers’ performance metrics like availability, CPU, disk space, and memory utilization.
OpManager comes with more than 100 built-in reports. Each can be scheduled, customized, and exported as needed. The product is available in three versions: Free, Essential and Enterprise. They differ in the number of devices they can monitor–from 10 to 10 000–and their feature set, with higher versions sporting more advanced features.
Icinga is another open source monitoring platform. It has a clean user interface and a feature set that can rival some of the best commercial products. Like most similar packages, Icinga uses SNMP to gather usage data from devices. One of the areas where Icinga particularly shines is its use of plugins. There are thousands of them to perform various monitoring tasks and extend the product’s functionality. And if you can’t find the right plugin for your needs, you can always write one yourself.
Icinga’s alerting and notification features are also among its strong suits. Alerts are fully configurable as to what triggers them and how they are transmitted. Another cool feature is segmented alerting that will let you send some alerts to some users and other alerts to different people for the best flexibility.
9. Spiceworks Network Monitor
The Spiceworks Network Monitor claims to be simple and easy to use. And it is. It is, after all, one of the most popular free network monitoring systems. Everything is free with the Network Monitor. Even the support. This is not something that’s commonly seen with free software. There’s a catch, though. This is not one of these highly scalable systems. On the contrary, this one was created with smaller networks in mind. It will perfectly suit you if your network has no more than 25 devices. While this is not much, it is certainly enough for many small businesses.
The tool’s dashboard can be customized to your needs. with a variety of color-coded graphs. Alerts are another major feature of the Spiceworks Network Monitor. Alert notifications are totally user-configurable and can be different for each device. However, although you can set alerting thresholds, you can’t create custom alerts to be notified of specific conditions. Another drawback of this tool is that it is ad-supported which can be annoying and unprofessional looking.
LogicMonitor claims to be “the leading SaaS-based performance monitoring platform for Enterprise IT“. And when it comes to cloud-based monitoring, it is, indeed, one of the best tools you can use. LogicMonitor will automatically detect devices on your network and start collecting data right after installation. It relies on over a thousand modules to assist users and automate monitoring and alerting. It can be used to monitor a wide range of devices and technologies, including cloud services from AWS or Azure. What’s more natural than monitoring cloud services with a cloud-based tool?
One of the best features of LogicMonitor is its forecasting engine. It can predict your future needs based on the current usage and trend. This is an excellent feature when looking at long-term capacity planning. LogicMonitor comes in three versions: Starter, Pro, and Enterprise. They differ by the number of services they can check and the data retention duration. You’ll need to contact LogicMonitor to get pricing information. A 14-days free trial is available.
Observium is an ideal network monitoring solution for organizations of all sizes. And if the user base is a testament to the tool’s quality, you’ll be glad to know that it is used by major players such as Yahoo, Twitch, and Spotify. Observium not only uses SNMP as its main protocol. It also uses LLDP, CDP, FDP, and EDP. Observium features autodiscovery which will add devices to your console and displays their operational parameters as graphs. The user interface features a very thorough overview page where you can see the whole network at a glance.
Observium also features threshold alerts which enable users to receive alerts when certain criteria are met. For instance, you could receive a notification whenever a device’s available memory drops below 70%. You could also receive a notification when a particular service goes down. Observium is available in two versions. Observium Community is available for free to everyone and is updated twice annually. Observium Professional adds priority access to daily updates and new features for a small yearly fee.
12. Zenoss Core
Zenoss Core might not be the best-known monitoring tool yet we felt it deserved a spot on our list due to its feature set and professional aspect. The tool can monitor many things such as traffic flows or services like HTTP and FTP. Zenoss Core has a clean and simple interface and its alerting system is excellent. We particularly loved the multiple alerting mechanisms that will alert a second person if the first one does not respond within a predefined delay.
On the downside, this is one of the most complicated systems to install and set up. The process is command-line driven. In this day and age of GUI installers, configurations wizards and autodiscovery, this may seem a bit archaic. Fortunately, there is ample documentation available and the end result makes it worth the installation efforts.
This list is far from complete. It could be twenty-five, fifty, or perhaps even on a hundred item long. We’ve picked those twelve tools we thought were the best. Any of them is a valuable tool that will assist network administrators in their monitoring efforts. With many of these products complementing each other in terms of feature set, it’s not rare to see organizations use a combination of tools for the best possible coverage of their monitoring needs. And with most of them being free or offering a free trial, there’s no reason why you can’t try several of them and see what best fits your needs.