Paessler PRTG

Strengthen your network's security with our port scanner PRTG

  • Monitor port status, bandwidth usage, and other key stats
  • Identify and fix potential vulnerabilities like open ports
  • Set custom alerts and get notified about issues near-instantly

Our users give top ratings for monitoring with Paessler PRTG



PRTG makes scanning your network's ports easy

Custom alerts and data visualizations make it easy to monitor, identify, and prevent resource bottlenecks, vulnerabilities, and other network issues.










A network with glitchy ports is like a house with broken doors

If your doors are stuck, the simple act of leaving one room and entering another can feel like an intense gym workout. And if they don't close properly, there's a risk anyone could come in. Even people who aren't welcome in your home.

Paessler PRTG is your comprehensive port scanner for tracking all your ports' key stats and alerting you promptly when they aren't working as they should. That means it's easier to clear the way if there are bottlenecks, and make sure those you want to keep out of your network stay out. 





3 reasons why to use PRTG as your port scanning tool

Relentless reliability

Network health issues don't take days off. And neither does PRTG. Our port scanner monitors your network devices round the clock, continuously checking the status of all ports and determining whether a port is open, closed, or hidden.

Robust security

With so much on your plate, potentially critical security issues can easily go unnoticed. PRTG keeps a close eye on switch ports, router ports, server ports, and other network infrastructure, rooting out weak spots before bad actors can exploit them.


Real-time alerts

Pick your preferred warning and error thresholds, and PRTG will ping you as soon as any of your network's ports are at risk of going under or over, so you can fix issues, and avoid security incidents and network disruption without breaking a sweat.



IT experts agree: Paessler PRTG is a great solution for IT infrastructure monitoring


“All-around winning
network monitor”

logo it brief

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


“PRTG Network Monitor
is very hard to beat”


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








What port scanning looks like in PRTG

Diagnose network issues by continuously monitoring ports across your network. Show port status, data transfer speed, and other key stats  in real time and visualize data in graphic maps & dashboards to identify problems more easily. Gain the visibility you need to troubleshoot speed issues, security vulnerabilities, and other port problems. 


Your port scanner at a glance – even on the go

Set up PRTG in minutes and use it on almost any mobile device.


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



PRTG monitors these vendors and applications in one view!


vendors vm ware



Easily find the source of the problem with our PRTG port scanning solution

Real-time alerts and custom notifications make it easy to solve network vulnerabilities and other issues.



“Excellent tool for detailed monitoring. Alarms and notifications work greatly. Equipment addition is straight forward and server initial setup is very easy. ...feel safe to purchase it if you intend to monitor a large networking landscape.”

Infrastructure and Operations Engineer in the Communications Industry, firm size 10B - 30B USD

Read the entire review at Gartner Peer Insights 








Perfect for networks of all shapes and sizes

With more than 250 preconfigured PRTG sensors and the flexibility to create custom sensors, plus unlimited monitoring capabilities, PRTG can handle any network with ease, regardless of scale and complexity.

PRTG's dedicated port scanning sensors include:

Port sensor

The Port sensor that alerts you when a specific port is not available

Port Range sensor

The  Port Range sensor that can monitor all TCP/IP ports within a given range simultaneously and shows you open and closed ports

SSL Security Check sensor

The  SSL Security Check sensor you can use to find out which security protocols a particular device supports




PRTG is compatible with all major vendors, products, and systems

vendors applications blue


PRTG makes scanning your network's ports easy

Custom alerts and data visualizations make it easy to monitor, identify, and prevent resource bottlenecks, vulnerabilities, and other network issues.



Create innovative solutions with Paessler’s partners

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


By integrating PRTG with Martello iQ, you can add a fast analytics layer to improve uptime, visualize your IT environment, and integrate all of your IT systems into a single pane of glass.

Read more


Paessler and Plixer provide a complete solution adding flow and metadata analysis to a powerful network monitoring tool.

Read more


Siemon and Paessler bring together intelligent building technology and advanced monitoring and make your vision of intelligent buildings and data centers become reality.

Read more


Scanning ports: FAQ


1. What is a port?

Ports are endpoints that make it easier for all the different processes and services on your network to talk to each other. When ports are working as they should, data flows freely and your network runs smoothly. But when ports are misconfigured or have other issues, they can slow your network down and make you more vulnerable to trojans and other security risks.

Ports are part of a network address (IP address). They ensure connections and data packets are assigned correctly and allow for the processing of services on the Internet. This may involve the transfer of files (ports 20 and 21), the sending of an email (port 25), or the assignment of names to an IP address (Port 53). Ports use a transport protocol to transmit information. Each port is assigned a non-random number. These numbers range from 0 to 65535, with 1 to 1023 used for Internet protocols.

2. What is a transport protocol?

A transport protocol – aka a “network protocol” – specifies how data is to be exchanged between the components in a network. In other words, it defines the way in which data is transmitted. The two most common protocols are the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP). PRTG can be used as a port scanner for both TCP and UDP.

3. What is a port scanner?

A port scanner is a tool that checks the status of ports. It uses queries to determine whether a port is open, closed, or hidden.

  • Open port: The computer accepts the query, responds, and asks what to do next.
  • Closed port: The computer responds to the query and indicates that the port is in use and therefore unavailable.
  • Hidden port: The computer provides no response to the query. The port may be hidden, filtered, locked, or blocked.

Some port scanners also scan open ports for additional information (such as the operating system in use), but this is not their primary purpose.

4. How does a port scanner function?

Port scanners work in a variety of ways. The simplest (and most common) way involves the uninterrupted transfer of data to a specific host. The port scanner notifies the system as soon as a data packet reaches an open port. Data packet types can also vary: TCP, UPD, ICMP, FIN, and ACK are just a few examples.

Port scanners can scan both vertically and horizontally. With vertical scans, a single network address is scanned on multiple ports. Horizontal scans, on the other hand, test several network addresses on a specific port (e.g., port 80).

5. What's the difference between port scanning and port monitoring?

Port monitoring is like surveillance, while port scanning is an inspection. A port monitoring tool helps you track overall performance and identify long-term trends. A port scanner, on the other hand, is how you spot potentially imminent threats, such as ports that are open when they should be closed.

6. How does PRTG port scanner work?

PRTG port scanner regularly sends network requests to your chosen port and tracks how long it takes for the port to receive it. This enables it to identify whether the port is open or closed, and what devices, applications, or other services it's being used for.

PRTG is designed to scan ports using TCP. But you can also scan ports using UDP by creating a custom script.

7. 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.


We asked: would you recommend PRTG?
Over 95% of our customers say yes!


Paessler AG conducted trials in over 600 IT departments worldwide to tune its network monitoring software closer to the needs of sysadmins.
The result of the survey: over 95% of the participants would recommend PRTG – or already have.


Recommend PRTG


PRTG the multi-tool

PRTG: The multi-tool for sysadmins

Adapt PRTG individually and dynamically to your needs and rely on a strong API:

  • HTTP API: Access monitoring data and manipulate monitoring objects via HTTP requests
  • Custom sensors: Create your own PRTG sensors for customized monitoring
  • Custom notifications: Create your own notifications and send action triggers to external systems
  • REST Custom sensor: Monitor almost everything that provides data in XML or JSON format


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 port scanning with PRTG and see how it can make your network more reliable and your job easier.



Network Monitoring Software - Version (May 2nd, 2024)


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


English, German, Spanish, French, Portuguese, Dutch, Russian, Japanese, and Simplified Chinese


Up to 100 sensors for free (Price List)

Unified Monitoring

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

Supported Vendors & Applications

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