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Paessler PRTG

All-in-one server monitoring & network monitoring software


  • Monitor all types of servers plus your entire IT infrastructure
  • Custom real-time alerts notify you before issues occur
  • Eliminate problems with server performance & bottlenecks
  • Reduce costs by improving stability & reducing server downtime

Monitor all your servers & hosts: Mail servers, web servers, database servers, file servers, virtual servers & more


Our users give top ratings for monitoring with Paessler PRTG




PRTG makes server monitoring easy

Custom alerts and data visualization make it easy to monitor, identify, and prevent server issues.


3 reasons to choose PRTG server monitoring


Integrated monitoring solution

Paessler PRTG monitors your entire infrastructure & servers, including processors, memory, cooling fans, power supplies, and more.

  • Adapts dynamically to the size of your server landscape
  • Quickly recognizes if a router or switch fails & causes a disruption
  • Virtual servers are automatically discovered & monitored

Custom alerts via email, SMS and more

PRTG alerts ensure that system failures are only short-lived or even prevented.

  • Email, SMS, push notifications, and more alert you faster if complications arise
  • Locate errors directly to save time
  • Customize alert threshold values to be notified before an issue leads to a crash

Better future capacity planning

PRTG simplifies capacity planning to save you time and money.

  • Recognize the need to increase capacity sooner
  • Detailed reports for scheduling and process optimization
  • Dashboards & maps help win over the management

Professional unified server monitoring software

Server types monitored by PRTG

PRTG monitors all types of servers – even in distributed networks. Here are a few examples of the kinds of servers for which PRTG provides predefined sensors so that you can start monitoring servers immediately.

How PRTG defines sensors (FAQ)


Mail server monitoring

Mail servers pose sensitive issues. When mail server glitches occur, employees are quick to complain, putting the support department under intense strain. With PRTG, you can monitor your mail servers round the clock and be alerted in a timely fashion. IMAP, POP3, SMTP, and more: we supply more than a dozen sensors for your mail server monitoring.

Sensors for mail server monitoring

Web server monitoring

Website performance can determine the fate of many companies. Downtime is costly from the very first moment. That’s why PRTG also makes a whole range of sensors available for your web server monitoring (IIS, Apache, and more).

Sensors for web server monitoring

Database server monitoring

Most departments live & die by database performance. PRTG offers a variety of sensors for immediate use for the monitoring of MySQL, Microsoft SQL, or Oracle SQL. Choose HTTP content or perform database queries for your SQL server monitoring.

Sensors for database server monitoring

File server monitoring

Administrators must ensure that the file server runs smoothly, so it’s common for them to search for a specific FTP server monitoring tool. But PRTG has you covered with around 20 preconfigured sensors for file server monitoring, including NAS devices and storage area networks (SAN)

Sensors for file server monitoring

Virtual server monitoring

In many companies, virtual servers are already a part of the IT structure. And for good reason: memory, hard disk space, and computing power can be allocated to individual applications dynamically. Resources are thus used in a considerably more efficient manner. PRTG monitors your virtual servers, right down to the very last detail.

Sensors for virtual server monitoring

Unlimited server monitoring

With PRTG, you get several other predefined sensors which provide an overview of your entire server landscape. Create custom sensors whenever you want, and use the API to adapt PRTG to any special use case.

More server sensors


Start server monitoring with PRTG and see how it can make your network more reliable and your job easier.


What server monitoring looks like in PRTG


Diagnose network issues by continuously monitoring all your servers and hosts. Show server status in real time and visualiza data in graphical maps & dashboards to more easily identify problems. Gain the visisbility you need to troubleshoot server issues and prevent problems.



Free ping monitoring vs. licensed editions




Server monitoring freeware


  • 100 sensors free for life (enough for basic server monitoring)
  • For each device about 10 sensors required on average
  • Alarm, mapping, and report features included
  • Freeware edition sufficient for most small networks

Our licenses

PRTG licenses


  • Flexible licenses with 500 to 10,000 sensors
  • Monitor 50 to 1,000 devices or more
  • Easily upgrade if more sensors are required
  • Existing monitoring unchanged with upgrade
  • Try full version free for 30 days

Trusted by 500,000 users and recognized by industry analysts as a leader



“Save two weeks working
weeks per year”


“All-around winning
network monitor”

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“The real beauty of PRTG is the endless possibilities it offers”


“Outstanding cloud


PRTG makes server monitoring easy

Custom alerts and data visualization make it easy to monitor, identify, and prevent server issues.


PRTG is compatible with all major vendors & manufacturers


vendors applications blue


Virtual server monitoring with PRTG

virtual server monitoring

Complete overview

Virtualized servers are complex. Malfunctions at the hardware level also affect virtual machines. PRTG gives you a complete overview at all times as a monitoring solution for your entire virtual environment.

Create a foundation that enables your efficient data structures to run as smoothly as possible – and watch as the improved utilization pays off.


Custom fit

PRTG can monitor almost any virtual infrastructure including Microsoft Hyper-V, Citrix XenServer, Nutanix, VMware, and more.

As a VMware technology partner, our server monitoring tool offers predefined PRTG VMware sensors for different purposes as well as sensors for many other vendors.



PRTG is fast and easy to upgrade and adapts to your growth dynamically. New sensors can be easily applied in minutes, reducing your time and effort in managing your server monitoring solution. This is particularly important since virtual servers are often introduced when a company is in the midst of vigorous growth. 


Host monitoring for virtual servers


In virtual environments in particular, it's important to monitor all your hosts. Host monitoring with PRTG allows you to constantly keep track of the availability and performance of your host. Especially if multiple VMs are running on one host, it's absolutely crucial to ensure a proper allocation of resources.

Host monitoring can also be important for web servers.

Whether you want to monitor physical or virtual servers, with PRTG you always keep an eye on the proper functioning of your hosts.


Your server monitoring at a glance – even on the go

PRTG is set up in a matter of minutes and can be used on a wide variety of mobile devices.


PRTG comes with all the features you need, plus more your IT infrastructure won't want to live without.

vendors vm ware


PRTG monitors these vendors and applications, and more, in one view!



The benefits of PRTG server monitoring


Get real-time updates

Server monitoring lets you monitor your servers in real time with regard to availability, accessibility, capacity, and overall reliability.

  • Status constantly updated
  • Check server status any time

Improve stability

Sysadmins monitor their servers because they wish to improve the stability and performance of their networks.

  • Set custom thresholds
  • Get real-time alerts
  • Complete your everyday tasks
  • Have a constant overview of resources

Analyze & optimize

Sysadmins analyze the values they receive from their monitoring software to develop courses of action.

  • Data-based optimization
  • Capacity planning
  • Custom PRTG reports

Try our Multi Server Simulator

Now you can test the behavior of your network before setting up a collection of new servers. It's easy with our Multi Server Simulator. See how your network reacts – and which areas need some work.

Try the Multi Server Simulator


PRTG makes server monitoring easy

Custom alerts and data visualization make it easy to monitor, identify, and prevent server issues.


Predefined sensors for server products

PRTG includes predefined sensors for server computers of different vendors.


 Vendor PRTG sensors for server monitoring
  • HPE 3PAR sensors
  • SNMP HPE BladeSystem sensors
  • SNMP HPE ProLiant sensors
  • Dell EMC Unity sensors
  • Dell PowerVault sensors
  • SNMP Dell EqualLogic sensors
  • SNMP Dell PowerEdge sensors
  • SNMP Cisco UCS sensors
  • SNMP IBM System X sensors



HPE Enterprise Partner

HPE Partner Ready for Technology Partner Program

Thanks to our multi-purpose monitoring tool and the comprehensive support we offer for HPE products, we have been asked to participate in the Hewlett Packard Enterprises Partner Ready for Technology Partner Program.

This technology partnership with Hewlett Packard Enterprises helps us to effectively develop new solutions, and proves that PRTG integrates well with software created by HPE.


LDAP monitoring with PRTG


LDAP at a glance


Lightweight Directory Access Protocol (LDAP) is a protocol that queries information from ditributed directory services. Directories contain object-related data which monitoring tools like PRTG that support LDAP monitoring can read. One such directory is Active Directory, the Microsoft service created for use in a Windows Server environment.

Getting started with LDAP monitoring


PRTG comes with a preconfigured LDAP sensor out of the box. This sensor connects to the LDAP server using distinguished name (DN) authentication, and displays the response time of your LDAP server if both connection attempt and authentication are successful.


arne seifert

„Hey Arne, how do I avoid false alarms during server maintenance?“

“In practice, repairs in the short-term will be necessary. While working, your monitoring will not trigger false alarms. The one-time maintenance window allows you to pause monitoring for each individual device or device group. For regular maintenance, with PRTG you can easily create an automated schedule.”

Arne Seifert, technical support at Paessler AG


HTTP server error messages


Common server errors


All status codes that begin with “5” (5XX) are server errors – and therefore a problem. Server error 500 is a collective status code for unexpected server errors. All other server errors (501, 502, 503, etc.) are used to flag specific problems.

Error 503, for example, means that the website’s web server is currently overloaded or unavailable. For more information, see our Knowledge Base articles about HTTP status codes and HTTP response codes.

Web server monitoring


Error messages are clear evidence that web server monitoring makes sense. All the more so if the website is an important tool for the company. PRTG comes with a full range of HTTP sensors for monitoring websites as well as individual URLs.


quote markus puke

“We can all work with greater peace of mind knowing
that our systems are constantly being monitored.”

Markus Puke, Network Administrator, Schüchtermann Klinik, Germany


“Easy to implement and configure with good technical support.”

R. v. S., ICT Manager at Heinen & Hopman Eng BV


Start server monitoring with PRTG and see how it can make your network more reliable and your job easier.



Create innovative solutions with Paessler’s IT partners

Partnering with innovative IT vendors, Paessler unleashes synergies to create
new and additional benefits for joined customers.


The PRTG SLA plugin from CORP IT, allows monitoring data in PRTG to be extracted and pulled into your existing SLA reporting tools, such as SQL Server Reporting Engine or Crystal Reports.

Read more


With ScriptRunner, Paessler integrates a powerful event automation platform into PRTG Network Monitor.

Read more


UVexplorer integrates tightly with PRTG to bring fast and accurate network discovery, detailed device inventory, and automatic network mapping to the PRTG platform.

Read more
















Video: Why PRTG server monitoring is important


PRTG makes your job easier

Our monitoring software frees you to focus on other tasks by promptly notifying you of potential issues.


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Save effort

PRTG gives you one central monitoring tool for your servers and entire network. Enjoy a quick overview of your whole infrastructure via our dashboard and app.

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Save time

Getting started with PRTG is a breeze. Setting up or switching from another network monitoring tool is easy thanks to the auto-discovery and pre-configured device templates.

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Save money

80% of our customers report substantial cost savings with network monitoring. Your costs of licenses will likely pay for themselves within weeks.



Easy setup, try PRTG for free today

Custom alerts and data visualization make it easy to monitor, identify, and prevent server issues.


Learn about Redfish sensors


From PRTG 21.3.70 on, we released our first Redfish sensors.

With Redfish sensors, you can monitor server hardware in the datacenter using the Redfish protocol from the servers' management controllers like Lenovo XClarity, HPE iLO, or Dell iDrac. Redfish is the successor of IPMI and provides better security.

Redfish System Health sensor

This sensor monitors the overall system status and the status of various components such as power supplies or PCIe devices, if available.

Redfish Virtual Disk sensor

This sensor monitors the virtual disk of a Redfish Scalable Platforms Management API (Redfish)-capable server.

Redfish Power Supply sensor

This sensor monitors the power supply of a Redfish Scalable Platforms Management API (Redfish)-capable server.


Server & server monitoring FAQs



Why is server monitoring important?

Servers are the backbone of your business. To minimize downtime and to ensure peak performance of your website and services, constant monitoring of your server infrastructure and your data center is vital.

By tracking the uptime, health, disk space, and performance of your servers, you can prevent outages and identify bandwidth hogs. In addition, you lay the foundation for delivering great service to your customers.


Basic server monitoring FAQs


1. What is a server?

A server is a computer or system that provides resources, data, services, or programs to other computers, known as clients, over a network. In theory, whenever computers share resources with client machines, they are considered servers. There are many types of servers, including web servers, mail servers, and virtual servers.

An individual system can provide resources and use resources from a different system at the same time. This means that a device can be both a server and a client at the same time.

History of servers

Some of the first servers were mainframe computers or minicomputers. Minicomputers were much smaller than mainframe computers, hence the name. However, as technology progressed, they ended up becoming much larger than desktop computers, which made the term microcomputer somewhat farcical.

Initially, such servers were connected to clients known as terminals that did not do any actual computing. These terminals, referred to as dumb terminals, existed simply to accept input via a keyboard or card reader and to return the results of any computations to a display screen or printer. The actual computing was done on the server.

Later, servers were often single, powerful computers connected over a network to a set of less-powerful client computers. This network architecture is often referred to as the client-server model, in which both the client computer and the server possess computing power, but certain tasks are delegated to servers. In previous computing models, such as the mainframe-terminal model, the mainframe did act as a server even though it wasn’t referred to by that name.

As technology has evolved, the definition of a server has evolved with it. Today, a server may be nothing more than software running on one or more physical computing devices. Such servers are often referred to as virtual servers.


2. How does a server work?

To function as a server, a device must be configured to listen to requests from clients on a network connection. This functionality can exist as part of the operating system as an installed application, role, or a combination of the two.

Microsoft’s Windows Server operating system, for example, provides the functionality to listen and respond to client requests. Additionally installed roles or services increase the types of client requests the server can respond to. An Apache web server, for example, responds to Internet browser requests via an additional application, Apache, that is installed on top of an operating system.

When a client requires data or functionality from a server, it sends a request over the network. The server receives this request and responds with the appropriate information. This is the request-and-response model of client-server networking, also known as the call-and-response model.

A server will often perform numerous additional tasks as part of a single request and response, including verifying the identity of the requestor, ensuring that the client has permission to access the data or resources requested, and properly formatting or returning the required response in an expected way.

Servers can be designed to do a single task, such as a mail server, which accepts and stores emails and then provides them to a requesting client. Servers can also perform several tasks, such as a file and print server, which both stores files and accepts print jobs from clients and then sends them on to a network-attached printer.


3. What types of servers are there?

There are many types of servers that all perform different functions. Many networks contain one or more of the common server types:

File servers

File servers store and distribute files. Multiple clients or users may share files stored on a server. In addition, centrally stored files offer easier backup or fault tolerance solutions than if administrators try to provide security and integrity for files on every device in an organization. File server hardware can be designed to maximize read and write speeds to improve performance.

Print servers

Print servers allow for the management and distribution of printing functionality. Rather than attaching a printer to every workstation, a single print server can respond to printing requests from numerous clients. Today, some larger and more high-end printers come with their own built-in print server, which removes the need for an additional computer-based print server. This internal print server also functions by responding to print requests from a client.

Application servers

Application servers run applications instead of client computers running applications locally. Application servers often run resource-intensive applications that are shared by a large number of users. Doing so removes the need for each client to have sufficient resources to run the applications. It also removes the need to install and maintain software on many machines as opposed to only one machine.

DNS servers

Domain Name System (DNS) servers are application servers that provide name resolution to client computers by converting names that are easily understood by humans into machine-readable IP addresses. The DNS system is a widely distributed database of names and other DNS servers, each of which can be used to request an otherwise unknown computer name. When a client needs the address of a system, it sends a DNS request with the name of the desired resource to a DNS server. The DNS server responds with the necessary IP address from its table of names.

Mail servers

Mail servers are a very common type of application server. Mail servers receive emails sent to a user and store them until they are requested by a client. Email servers need to be properly configured and integrated in the network. They can then send and receive messages rather than requiring every client machine to have its own email subsystem that is continuously running.

Web servers

A web server is a special kind of application server that hosts programs and data requested by users across the Internet or an intranet. Web servers respond to requests from browsers running on client computers for web pages or other web-based services. Common web servers include Apache web servers, Microsoft Internet Information Services (IIS) servers, and Nginx servers.

Database servers

Database servers run database applications and respond to numerous requests from clients. Common database server applications include Oracle, Microsoft SQL Server, DB2, and Informix. The amount of data used by companies, users, and other services is staggering. Much of that data is stored in databases. Databases need to be accessible to multiple clients at any given time and can require extraordinary amounts of disk space. Both of these needs lead to locating such databases on servers. 

Virtual servers

Unlike traditional servers that are installed as an operating system on machine hardware, virtual servers exist only as defined within specialized software called hypervisor. Each hypervisor can run a huge number of virtual servers at the same time. The hypervisor presents virtual hardware to the server as if it were real physical hardware. The virtual server uses the virtual hardware as usual, and the hypervisor passes the actual computation and storage needs onto the physical hardware beneath, which is shared among all the other virtual servers.

Proxy servers

A proxy server acts as an intermediary between a client and a server. It is often used to isolate either the clients or servers for security purposes. A proxy server takes the request from the client and instead of responding to the client, it passes the request on to a different server or process. The proxy server receives the response from the second server and then replies to the original client as if it were replying on its own. This way, neither the client nor the responding server need to directly connect to each other.

Monitoring and management servers

Some servers exist to monitor or manage other systems and clients. There are many types of monitoring servers. Several of them listen to the network and receive every client request and server response, but some do not request or respond to data themselves. This way, the monitoring server can keep track of all traffic on the network, as well as the requests and replies of clients and servers, without interfering with those operations.

4. What server structures are there?

The concept of servers is nearly as old as networking itself. After all, the point of a network is to allow one computer to talk to another computer and distribute either work or resources. Computing has evolved since then, resulting in several types of server structures and hardware.

Mainframe or minicomputer (AS/400)

The original servers, mainframe computers, and later minicomputers, handled almost all computing tasks except the interaction with the user through a screen and keyboard, which was left to the client system.

Computer hardware server

The next major wave of servers included computer-based servers. In many respects, these servers were nothing more than larger, more powerful desktop computers. Such servers were generally more expensive and held far more memory and disk space than most client computers. Each server was still a self-contained unit with its own motherboard, processor, memory, disk drives, and power supply. Servers like this were often warehoused in air-conditioned rooms called server rooms, and were later bolted into racks for better storage and accessibility.

Blade servers

The original computer server hardware was large and stored in racks that could hold hundreds of pounds. Over time, however, faster means of connecting hardware resulted in parts of the server being extracted from a single, self-contained device. By removing hard drives, eliminating internal cooling, and the ongoing miniaturization of computing parts, servers were eventually reduced to a single thin server known as a blade server. While still stored in racks in server rooms, blade servers are smaller and can be replaced more easily.

Combining servers

Even before virtualization, servers were being extracted from the standard model of a single server operating system installed on a hardware machine. Technology, such as network-attached storage, removed the need for a server to have its own storage. Other technologies, such as mirroring and clustering, enabled pieces of hardware to be combined into larger, more powerful servers. Such a server might consist of several blades, several attached storage devices, and an external power supply, and each piece could be swapped out for another while the server was still running.

Virtual servers

Virtual servers still require hardware, but that hardware now runs a different process known as a hypervisor. In some cases, such as Microsoft’s Hyper-V, a full operating system continues to run on the hardware itself. In other cases, so-called bare-metal hypervisors can be installed directly onto server hardware. In both instances, the hardware itself is often spread across an array of blade servers, networked storage, and power supply.


5. What examples of server operating systems are there?

Microsoft Windows Servers

An argument can be made that Windows for Workgroups was Microsoft’s first server operating system. In that version, specific computers could be set to share resources and respond to requests from clients, which made them servers by definition. Microsoft’s first real server operating system was Windows NT. Its 3.5 and 3.51 versions ran on many business networks until Microsoft released its Windows Server line that continues to exist today. 

Linux/Unix servers

The other major player in server operating systems is the Linux/Unix realm. There are multiple versions and flavors of Linux/Unix including Red Hat Enterprise Linux, Debian, and CentOS. As an open-source operating system, Linux is very popular as a web server, an often has the Apache web application server installed.


Although no longer produced, NetWare was a major player in the server software space as the client-server era was ramping up. Eventually, NetWare moved its server operating system to a Linux-based kernel and named it Novell Open Enterprise Server (OES).

Cloud servers

Virtual servers hosted on a third-party infrastructure on an open network, such as the Internet, are called cloud servers. There are numerous cloud server providers these days, including Google’s Cloud Platform, Microsoft Azure, and IBM Cloud.
However, the main pioneer of corporate cloud computing was Amazon’s AWS platform. It originally started using the spare capacity of Amazon’s own servers and networks, but AWS now allows customers to create a virtual server nearly from scratch and then adjust the amount of resources that server can use.

6. What is a sensor in PRTG?

In PRTG, “sensors” are the basic monitoring elements. One sensor usually monitors one measured value in your network, for example the traffic of a switch port, the CPU load of a server, or the free space on a disk drive.

On average, you need about 5-10 sensors per device or one sensor per switch port.


5 common server monitoring questions 

1. How can I best protect my company from server failures?

When a server goes down, the IT department must quickly take action. PRTG helps you improve the reliability of your servers. If the load of individual hardware components such as CPU, hard drives, or RAM rises, you’ll be notified at once and can react, for example, before a server fails. With PRTG, you can set custom threshold values that suit your individual requirements.

2. Can I monitor external servers from one central location?

PRTG can monitor your servers from one central location, even if the servers are located in distributed networks that are separated with a firewall from your LAN. For this purpose, you can install a PRTG remote probe in your remote network which collects monitoring data independently from the PRTG core server and sends it back there via a TLS-secured connection. This way, you always have all your data in a central overview.

3. What information is collected by the PRTG server monitoring tool?

What kind of information PRTG collects heavily depends on the type of server that you want to monitor as each server type has different monitoring requirements. 

There are many monitoring and analysis tools on the market. We recommend weighing the pros and cons of each (such as PRTG vs. Nagios). PRTG is a comprehensive network monitoring tool that not only does your server monitoring tasks for you, but also continually monitors your entire IT environment. This environment includes servers as well as devices such as switches and routers from all major manufacturers, applications, services, network traffic, and much more.


4. How does PRTG trigger an alarm if there is a server malfunction?

You yourself set the threshold values which, when exceeded, activate the sending of a warning message. You can also define how the message is sent. Options include email, push notification, SMS, syslog messages, and more. The PRTG alarm is fully customizable. You can, for example, set up a more rigorous notification system for critical infrastructures (such as your servers) than for individual workstations.

5. Will monitoring have a negative impact on network performance?

PRTG sensors use a variety of protocols to monitor your network and servers. These include SNMP (Simple Network Management Protocol), WMI (Windows Management Instrumentation), or Windows performance counters. WMI is a commonly used standard created by Microsoft. Running WMI often puts great strain on the load of a network. If you decide to go with WMI, you should create as few WMI sensors as possible to ensure that you don’t compromise the performance of your network. By contrast, the load generated by SNMP is quite insignificant, even for extensive monitoring with several thousand sensors. You’ll therefore rarely encounter drops in performance.


Still not convinced?




More than 500,000
sysadmins love PRTG

Paessler PRTG is used by companies of all sizes. Sysadmins love PRTG because it makes their job a whole lot easier.


Monitor your entire IT infrastructure

Bandwidth, servers, virtual environments, websites, VoIP services – PRTG keeps an eye on your entire network.


Try Paessler PRTG
for free

Everyone has different monitoring needs. That’s why we let you try PRTG for free.


Paessler PRTG

Start server monitoring with PRTG and see how it can make your network more reliable and your job easier. 




Network Monitoring Software - Version (May 24th, 2023)


Download for Windows and cloud-based version PRTG Hosted Monitor available


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Network devices, bandwidth, servers, applications, virtual environments, remote systems, IoT, and more

Supported Vendors & Applications

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