The top 10 agentless network monitoring tools

network monitoring tools
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September 06, 2022

To help you choose the option best for you, we will discuss what agentless monitoring really is, what you should look for when choosing an agentless network monitoring tool, and our top 10 picks from the tools available today.

Having the right monitoring tool is important for efficient networking monitoring and management. However, you can’t install an agent on all the devices that you need to monitor, such as network switches and routers and even certain desktop systems and servers. This is where agentless IT monitoring tools come in handy.

But which agentless network monitoring tool should you use? Before answering, let’s go through the basics and offer you an overview of what you’ll be seeing in this article. Feel free to jump to the section that is more interesting to you:

What is agentless network monitoring?, How to choose the right tool?

Monitoring tool vendors:

Paessler PRTG, Zabbix, ManageEngine, SolarWinds NPM, Solarwinds Server & Application Monitor, WhatsUpGold, Nagios, Site 24×7, OP5 Monitor, LogicMonitor

What is agentless network monitoring?

Agentless monitoring is essentially a kind of network monitoring comprising a monitor that collects different performance metrics from a particular device. However, unlike agent-based monitoring, agentless monitoring doesn’t require a software agent to be installed on the server or device being monitored. Instead, agentless monitoring tools use other means to collect the required data. 

Not only does agentless monitoring remove the challenges of installing a software agent on the target device, it also doesn’t have the additional overhead that is usually associated with agent-based tools. Plus, with agentless monitoring, you don’t need to deal with software configuration on the target machine or worry about updating the software every now and then.

But the greatest benefit of agentless monitoring is that it’s much easier to expand your network without having to install the software on each device you add. As a result, setting up and monitoring your network is much easier. 

How to choose the right agentless monitoring tool

Given the plethora of agentless network monitoring tools available today, it is important to understand what separates good tools from average ones. Below, we have identified some important factors to look out for when choosing a tool.

Ease of use and setup

No one wants to deal with the hassle of setting up and using an overcomplicated tool, which is why ease of use and setup is important. If the tool is hard to set up, you will have to spend more time trying to figure out how it works than actually using it. If it’s not intuitive, you might be reluctant to use it in the first place.

Ideally, the network tool you choose should feature an auto-discovery function that discovers network devices automatically. The user interfaces should also be easy to use, with a variety of interface options to choose from.

Detailed insights

Detailed insights into the operational data are important in order to understand what’s really going on with your network. This is why the ideal tool should allow you to visualize the network, as well as its single components, in one interface in the form of diagrams, graphs, maps, and dashboards. It should also provide you with customization and drill-down options for further detailed insights.

Another handy feature to have is reporting functionalities, and it’s best if the tool allows you to schedule reports. 

Error reporting

The best tool for the job should also have an advanced alerting mechanism that uses different color codes to indicate different issues so that error reporting is easier. Additionally, it should be able to send notifications over different communication channels so that you don’t miss out on any important issues and so that appropriate action can be taken. 

Similarly, the agentless networking tool you choose should also have a failure mechanism that ensures high availability in case the system that runs the tool fails.

Customer support

Sometimes, you might run into problems with the monitoring tool itself that you are unable to figure out on your own. In such cases, prompt and efficient customer support is always appreciated so that you can continue using the tool as soon as possible.

Free trial

It’s better if you choose a tool that offers a free trial of up to a month so that you can use the tool and make sure it’s the right one for your business before you spend a good amount on it. You don’t want to invest a hefty amount in a tool that doesn’t provide any real value for your business.

Almost all the agentless IT monitoring tools that we discuss below offer either a 14-day or 30-day trial period. However, it’s best if you opt for a product that offers a 30-day free trial, since 14 days may not be enough to test all the functionalities provided by the tool.


And finally, you need to consider the tool’s price. Always keep your company’s budget in mind and choose one that is affordable and, at the same time, provides value equivalent to the cost. Nearly all network monitoring tools on the list provide quote-based pricing, so you’ll have to get in touch with their customer support to know how much each tool will cost you.

Top 10 tools for agentless network monitoring

Keeping the features defined above in mind, we’ve narrowed down the list of the best agentless monitoring tools available today. Let’s look at them in more detail.

1.    Paessler PRTG Network Monitor

PRTG is an integrated tool you can use to monitor applications, traffic, performance, devices, bandwidth, cloud monitoring services, systems, and much more within an IT infrastructure. Compared to most other monitoring tools, PRTG is much easier and quicker to install.

What we love most about it though is the ease of setup and use it offers. You can install it with only a few clicks, and it comes with an auto-discovery feature that scans the network and adds elements to the setup automatically. In addition to a user-friendly website, PRTG also offers a desktop application and even a mobile app for both Android and iOS, making monitoring your network convenient and easy.

Paessler’s traffic monitoring interface on the iOS app
Paessler’s traffic monitoring interface on the iOS app

The browser interface isn’t just highly functional; it also makes navigation easy. Plus, the attention to detail that the company has given to the tool is very clear when you view the network map. It’s beautiful, although there’s a learning curve involved if you want to build said map. But once you get the hang of it, you can create detailed maps and display them on a big screen so that everyone has an overview of how the network is doing at a given point in time. You can also use the map rotation feature to show different views of the infrastructure.

The network monitoring tool is also vendor neutral and uses a number of technologies to integrate different network devices into the monitoring setup. These technologies include flow protocols like IPFIX, sFlow, NetFlow, and jFlow, as well as SSH, SNMP, and WMI. Deployment is much easier thanks to the plethora of preconfigured templates for sensors and devices for well-known providers and manufacturers.

paessler prtg dashboard user interface
Paessler’s customizable dashboard with real-time maps to visualize network

PRTG also allows you to view your data in an interactive and customizable dashboard. The maps also come with some visualization options as user-friendly drag-and-drop widgets that make things easier. Troubleshooting and problem solving are also made easy thanks to the customizable, real-time alerts. You can choose your preferred notification methods and even set individual notification triggers so that you don’t miss important notifications.  


  • Provides extensive support for most devices
  • Leverage SNMP, WMI, and packet sniffing to discover new devices and monitor network performance
  • Easy-to-make custom reports and views thanks to the drag-and-drop editor
  • Different notification options available
  • User friendly and suitable for IT professionals  


  • The plethora of features can be overwhelming and results in a steep learning curve
  • Difficult to configure custom sensors

2.    Zabbix

Zabbix is an open-source platform for system monitoring. It provides both agent-based and agentless options. In cases where it’s impossible to install a Zabbix agent, the Zabbix server makes agentless monitoring possible, enabling the monitoring of various aspects of your server infrastructure (both local and cloud based), such as network monitoring, application monitoring, and DB monitoring.

Unlike many other agentless monitoring tools, Zabbix also has an appealing web interface and provides customization and automation features. It also offers numerous preconfigured monitoring templates, allowing you to monitor devices from popular vendors right out of the box.

Zabbix’s monitoring dashboard
Zabbix’s monitoring dashboard

The tool’s list of features includes smart alerting that predicts trends, anomaly detection, issue classification based on severity (while letting users define different escalation scenarios), and root cause analyses. Plus, you can use regex to define flexible and intelligent thresholds, choose from various messaging channels to receive alerts, and define a customized message for different channels while keeping the receiver in mind. 

Another feature of Zabbix that we like is that it makes data visualization easy and provides numerous customizability options. You can use the drag-and-drop features to make widget-based dashboards and configure the widgets according to your needs.

What distinguishes Zabbix from other open-source tools is that it sells ancillary services, including five different levels of technical support as well as a certification training program. In comparison, most other open-source products only provide community-based support. It’s important to mention here that Zabbix’s community support is also commendable and available for free.  


  • Open-source, free monitoring platform
  • Enterprise-grade system for both small and large networks
  • No vendor lock-in
  • Offers high customizability 


  • You have to purchase ancillary services
  • Lots of manpower and time needed to set up, maintain, and customize the software 

3.    network-monitoring/" target="_blank" rel="noreferrer noopener">ManageEngine OpManager

OpManager from ManageEngine (famous for its network administration tools) is essentially an all-in-one infrastructure monitoring tool that you can use to monitor virtual and physical servers and network equipment. OpManager’s list of features includes an intuitive UI, so that you find the required information with ease, a commendable reporting mechanism, excellent reporting features, and built-in custom reports.

OpManager’s UI interface for mobile and iPad
OpManager’s UI interface for mobile and iPad

Just like PRTG, OpManager also offers mobile apps for both Android and iOS, allowing you to monitor and do basic troubleshooting even while on the go. The tool is available in three editions: the Standard and Professional editions for SMEs, and the Enterprise edition for larger organizations with up to 250 devices.

Let’s take a closer look at OpManager’s comprehensive list of features. These include numerous preconfigured network performance monitors to make integration and deployment easier, but most features, such as reports, distributed monitoring, and virtual environment monitoring aren’t available in the Standard edition. You will also have to purchase other features, including storage and firewall monitoring, as plugins and addons.

OpManager also provides automatic alerts in real time via email and SMS in case of breakdowns; however, it doesn’t offer different notification methods like other tools on this list do. But you can still set custom thresholds, such as multi-level thresholds, to classify issues according to different escalation levels. 

Clean, structured dashboard to monitor health, availability, and performance
Clean, structured dashboard to monitor health, availability, and performance

And finally, OpManager offers well-structured, simple, and clean dashboards to visualize the monitoring data that you can customize using different preconfigured widgets. But like most other features, real-time widgets are not available for the Standard edition. 


  • Infrastructure management tool that provides network monitoring and application performance management
  • Creating a map is easy and intuitive
  • Easy to use and install (on premise)


  • Limited features available in standard edition
  • Default installation doesn’t include reports

4.    SolarWinds Network Performance Monitor

SolarWinds provides two networking tools: the Network Performance Monitor (NPM) and the Server & Application Monitor. Let’s take a look at NPM first.

NPM tracks how network elements such as switches, applications, and servers are doing, provides support for nearly all network devices right out of the box, and is popular with medium to large companies. It also offers excellent network monitoring features such as SNMP and packet sniffing.

NPM makes network availability & performance monitoring easy
NPM makes network availability & performance monitoring easy

However, since the tool has a modular setup, the usability and setup can be complex. And while you can integrate NPM with additional tools, you will have to get separate solutions or addons for all the features that are beyond the scope of what the tool provides, such as flow, database, and server monitoring.

Just like most monitoring tools, you get preconfigured default alerts with NPM that you can customize based on your needs. You can also reduce alert noise with the scheduling feature and even specify when different team members get different notifications.

NPM’s maps and dashboards are also worth mentioning. The tool’s Network Atlas feature allows you to make customized maps with a drag-and-drop feature. It also creates L2 and L3 connections automatically between the chosen devices. Meanwhile, the visualization tool, NetPath, allows you to look at all the paths that your data takes within your network. You can even trace every hop!


  • Supports both packet analysis and SNMP as well as auto-discovery
  • Great and easy-to-use alerting features
  • Allow you to customize the dashboard with drag-and-drop widgets
  • Comes with preconfigured dashboards views, templates, and reports
  • Responsive and easy to use for both SMEs and large organizations


  • Tricky to use, particularly for those with a non-technical background

5.    SolarWinds Server & Application Monitor

Next, let’s look at SolarWinds’ Server & Application Monitor (SAM). SAM provides 1200+ monitoring tools for both Linux and Windows applications. Installation is a breeze and is very quick, too. A component monitor wizard makes it easy to configure application monitors and lets you set up sensors to monitor your network. Plus, the dashboard gives an overview of the application’s health as well as the application status.   

Easily manager servers and apps with SolarWinds’ server & application monitor
Easily manager servers and apps with SolarWinds’ server & application monitor

The tool makes it easy to monitor application dependencies since it automatically discovers servers and applications and adds the latter to a map of dependencies, allowing you to see your entire infrastructure at a glance. It also lets you set custom alert thresholds to identify anomalies, and you can even create reports to further inspect what’s really going on in your system. 


  • Specially designed for large enterprises
  • Auto-discovery builds inventory lists and network topology maps in real time
  • Supports packet analysis and SNMP
  • Drag-and-drop widgets let you customize the dashboard
  • Commendable reporting system that features preconfigured templates


  • Not for non-technical users; more suitable for system administrators

6.    WhatsUp Gold

WhatsUp Gold combines both configuration and log management with application and network performance monitoring. Just like most tools on our list, it has an auto-discovery feature, but it goes a step ahead of other tools and automatically generates L2 and L3 network topology that is automatically updated whenever there are changes in the network.

The tool’s list of features includes customizable notifications, real-time alerts, and the ability to define specific thresholds. Users can also specify critical application components to generate the most relevant alerts for components that can obstruct the network if they have issues. It also offers a customizable dashboard with color-coded symbols indicating the device status.     

WhatsUp Gold’s customizable dashboards help ensure optimal performance
WhatsUp Gold’s customizable dashboards help ensure optimal performance

WhatsUp Gold’s application monitoring capabilities are also quite detailed. With the application monitoring plug-in, you can monitor response times and web transcription scripts to identify issues. The tool also includes out-of-the-box monitoring profiles for Active Directory, SharePoint, SQL, and Microsoft Exchange. Meanwhile, the virtual monitoring plugin allows you to monitor virtualized environments. It accepts Hyper-V and VMware resources to ensure that the visibility reaches the hypervisor level.   

However, the tool doesn’t have any prebuilt integration templates. You’ll have to make REST API calls for third-party applications and systems integrations, so setup and configuration are a little tricky.


  • Simple visualizations give you insights at a glance
  • Intuitive UI
  • Monitors cloud-based applications, LANs, and WANs
  • Uses out-of-the-box alerts


  • Licensing policy isn’t transparent
  • Cloud-based version not available

7.    Nagios

Nagios is a Linux-based network monitoring tool to monitor business-critical infrastructure components. There are two versions of Nagios available: Nagios Core, which is a free, open-source tool, and Nagios XI, a commercial product. While both use the same underlying core, the free version uses community-developed plugins and addons for monitoring tasks while they are already included in the commercial product. 

Nagios XI’s web interface
Nagios XI’s web interface

Nagios is great for monitoring network infrastructures, systems metrics, network protocols, operating systems, applications, and services. And if you need something out of the box, you can use third-party addons. Nagios XI has both Enterprise and Standard editions. The former includes additional functionality as well as support for large-scale configurations, scheduled reporting, and forecasting. 

Comprehensive monitoring with Nagios Core
Comprehensive monitoring with Nagios Core

Like other monitoring tools, Nagios provides the notification and alerting functionalities, and you can get advanced learning options using addons. However, the biggest downside to Nagios is that the web interface is very unintuitive and the dashboards and user interfaces are not very visually appealing.


  • Open-source model; provides many community-developed APIs and addons
  • Provides a high level of customization
  • Nagios XI involves less scripting and configuration work


  • Unintuitive and visually unappealing UI
  • Configuring and setting up customizations require extensive time and knowledge

8.    Site 24×7

Site 24×7 is a server monitoring tool that provides both agent-based and agentless monitoring. You can use the tool to monitor end-users, applications, and IT infrastructures. While the latter can gather lots of information from your server and network, the former can gather a greater variety of data. For instance, the remote server can easily measure the RTT (round-trip time) to the target server; however, queries need to be executed on the target server to gather information.

Agentless server monitoring displaying all the processes on the chosen server
Agentless server monitoring displaying all the processes on the chosen server

Both the agentless and agent-based versions of the tool make use of the same console, but the set up differs. For the agentless version, you either need a range of addresses or an IP address that you can enter into the settings. Additionally, it uses WMI and SNMP to monitor servers.

The tool provides a feature called Real User Monitoring (RUM) that allows you to monitor problems with the network as well as the programs running on it. Along with that, you can even monitor what the people in your organization are looking at. This way, you can see the way users are experiencing the applications over the network and even refine segmentation and analysis. 

Other services provided by Site 24×7 included cloud cost managing, cost cuttings, and cloud cost savings. This way, you can set a budget and stick to it with decisions based on the data. The tool is available in 4 editions, but the free tool can only monitor 5 servers. 


  • Supports real user, infrastructure, and network monitoring
  • Leverages real-time data to build inventory reports, network maps, and charts
  • User friendly and has a free version available


  • You’ll need time to explore and understand all the features

9.    ITRS OP5 Monitor

OP5 Monitor is an open-source tool based on Naemon, which is a fork of Nagios. It is a highly scalable and flexible monitoring solution suitable for both big and small environments. You can use it to monitor your organization’s IT environment, whether in a public cloud, dynamic environments, on premise, or a combination of any of these.

View your entire organization on a single pane with OP5 Monitor’s infrastructure monitoring
View your entire organization on a single pane with OP5 Monitor’s infrastructure monitoring

OP5 Monitor claims to be an enterprise-level solution and, considering its features, that might just be true. In particular, it scales quite well in distributed environments, making it potentially suitable for enterprises. Let’s quickly look at all the features it provides.

The tool provides a completely customizable dashboard that you can use to display all the important information. Plus, OP5 Monitor’s alerting features are quite impressive – they don’t just trigger information, but they also launch event handlers or scripts that assist with self healing. Another great feature is that OP5 Monitor integrates with other systems like CRM and ticket management quite easily. Plus, the API is quite developer friendly, so you can easily extend its functionality.

The tool offers both a 30-day trial as well as a demo environment, which gives it another plus point.


  • Quite flexible, considering it’s based on Nagios
  • Impressive alerting feature
  • Suitable for both large and small enterprises


  • NetFlow is missing
  • UI isn’t too impressive


LogicMonitor is another network monitoring tool that’s mainly made for those with infrastructure assets in the cloud. As a result, it’s not designed like other agentless systems. Instead, it’s a SaaS system whose main interface is present on the cloud while a lightweight collector resides on the network, monitoring the performance and health of network traffic and devices.

And since this is a SaaS tool, there’s no on-premise installation involved. You can even set it up quickly using the auto-discovery feature that collects information about the IT infrastructure based on the IP addresses or hostnames that you enter. Once it is set up, it dynamically discovers new network devices.

This monitoring tool uses flow protocols, NBAR2, WMI, and SNMP to monitor network devices. Plus, it offers numerous integrations for well-known vendors to make deployment easy. We also like the intelligent alerting that clearly distinguishes between non-service-impacting and service-impacting alerts. Like other tools, customizing preset alert thresholds is also possible with LogicMonitor.

Another noteworthy feature is the clean UI. Plus, it’s easy to make your own dashboard thanks to the numerous, well-thought-out templates already available. And finally, you can visualize your data, including a hierarchical view of the equipment and a graphical topology map that helps you visualize your networks and quickly identify the root cause of any problems.

LogicMonitor’s network monitoring dashboard
LogicMonitor’s network monitoring dashboard

LogicMonitor offers only a 14-day trial period, which is pretty standard for cloud-based monitoring platforms; however, we believe that it isn’t really enough to fully understand if you should invest in it. The full version has two pricing plans: Enterprise and Pro. The latter includes AIOps for over 200 devices, while the former supports up to 199 devices.


  • Cloud-based service that doesn’t require on-premise installation
  • Clean, rich user interface
  • Ideal for geographically distributed sites
  • Easy to scale


  • Not for smaller networks
  • Needs web connectivity