Paessler PRTG

Transfer data packets safely
with PRTG SSL monitoring


  • icon check white 2
    PRTG uses SSL and TLS protocols to check devices

  • icon check white 2
    PRTG monitoring data can be accessed via SSL
  • icon check white 2
    Individual SSL certificates can be imported











SSL monitoring with PRTG

PRTG determines the extent to which your connections are protected

Safe data transmission via the Internet or the company network is one of the fundamental aspects of IT security. The instruments used to ensure safe data transmission are the hybrid cryptographic protocols Transport Layer Security (TLS) and its predecessor, Secure Sockets Layer (SSL). In order to transfer data safely, IT administrators must know which encryption possibilities are available to devices at any given time.

To avoid sending data via unsecured connections, SSL monitoring checks your devices for their SSL/TLS capabilities. To do so, PRTG has developed the SSL Security Check Sensor, which tests the selected device for its possibilities of being accessed via these security protocols. You can therefore learn if your connections are strong, weak, or not protected at all.

PRTG also lets you use SSL to encrypt your own monitoring data. For even this data may contain sensitive information, information which must be protected against unauthorized access while being sent across the company network. Individual SSL certificates can be imported for this purpose.

With PRTG, everyone will work with peace of mind.


This short video explains SSL certificate monitoring


Data collected by PRTG

Network infrastructure

SSL/TLS protocol versions accepted on a device’s port

Network infrastructure

Security ratings


How SSL monitoring with PRTG works

 i How PRTG defines sensors

In PRTG, “sensors” are the basic monitoring elements. One sensor usually monitors one measured value in your network, e.g. the traffic of a switch port, the CPU load of a server, the free space of a disk drive. On average you need about 5-10 sensors per device or one sensor per switch port.

View video (3:26 min.)


Device Port Sensor

The sensor on the device’s port establishes whether it can connect to the protocol (“accepted”) or if the connection is “denied,” and based on this information provides a sensor status:

  • SSL 2.0: weak security (“warning” if accepted, "up” if denied)
  • SSL 3.0: weak security (“warning” if accepted, "up” if denied)
  • TLS 1.0: weak security (“warning” if accepted, "up” if denied)
  • TLS 1.1: strong security (“up” if accepted, otherwise “gray”)
  • TLS 1.2: perfect security (“up” if accepted, otherwise “gray”)


SSL Security Check Sensor

The SSL Security Check Sensor monitors Secure Sockets Layer (SSL) connectivity on a chosen port on your device.

This sensor attempts to connect to various SSL/TLS protocol versions using the device’s specific TCP/IP port number, and returns a value that corresponds to whether or not the respective protocol is supported.


Security Rating

The security rating displays the connection security of the selected port by way of one of the following statuses:

  • Down: No security protocol is available. The sensor is unable to connect to any of the protocols.
  • Warning (weak): The sensor is able to connect to at least one of the weak protocols SSL 2.0, SSL 3.0, or TLS 1.0.
  • Up (strong): The sensor is only able to connect to one of the strong protocols TLS 1.1 or TLS 1.2. Connections to weak protocols are not possible.

This type of sensor uses lookups to determine the status values of one or more sensor channels. This means that the possible statuses are defined in a lookup file. You can change the behavior of a channel by editing this lookup file. For more details, see: Define lookups.

Additional information on this topic can be found in our knowledge base: How do you determine the protocol security ratings of the SSL Security Check sensor?


A sneak peek into SSL monitoring with PRTG


Quickly see which devices support which encryption – even while 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



quote john krull

“Our network engineers really love PRTG, because of its customization”

John Krull, CTO, Oakland Unified School District, USA


4 good reasons to choose PRTG as your SSL monitoring tool

Ensure secure data traffic

Ensure secure data traffic

Constant monitoring guarantees that security loopholes due to insufficient SSL/TSL capabilities are eliminated as quickly as possible.

Secure an overview

Secure an overview

Our dashboard provides a convenient overview of the status of the encryption that is supported by your devices’ ports.

Stay in the know

Stay in the know

If the security rating changes, you’ll be notified at once, wherever you happen to be.

Reduce workloads

Reduce workloads

Instead of checking device ports individually, you can simply rely on the PRTG sensors and notifications.


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


“Fantastic network and infrastructure monitoring solution that is easy to deploy and easier still to use. Simply the best available.”

Read more reviews

“Software is absolutely perfect, Support is superior. Meets all needs and requirements, this is a must have solution if you are needing any form of monitoring.”

Read more reviews

“The tool excels at its primary focus of being a unified infrastructure management and network monitoring service.”

Read more reviews


PRTG makes your job easier

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


time white

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.

brain white

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.

money white

Save money

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



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


Create innovative solutions with Paessler’s partners

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


Axis offers one of the most complete and reliable product portfolios, an expanded professional network, and comprehensive integration support for video management software.

Read more

IP Fabric

Combining the broad monitoring feature set of PRTG with IP Fabric’s automated network assurance creates a new level of network visibility and reliability.

Read more


dirk paessler

“Our top priority is to continue to develop PRTG is a constant, practical, and proactive manner. Our hope is that administrators will always be ready for any new standards which arise.”

Dirk Paessler, founder of Paessler AG in Nuremberg


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

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


Want to read more? Please do!

Website monitoring: Is your website always available? Are all its key processes operational? Are its load times increasing? With PRTG, you can monitor the worldwide availability of your website with the HTTP v2 and Cloud HTTP v2 sensors. The same goes for your servers and entire IT infrastructure.

Ping Monitoring: PRTG uses ping to check the availability of all your network devices. If the ping fails, you will be notified immediately.

Active Directory Monitoring: PRTG offers integrated complete Active Directory Monitoring in real time. Find out more about Active Directory Auditing here.

VPN Monitoring: PRTG monitors VPN connections and measures traffic, load, and the number of users. Identify connection problems and suspicious traffic.


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.

Still not convinced?


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. Start now with your trial.




Network Monitoring Software - Version (February 14th, 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

cisco logo grey 40 dell logo grey 40 hp logo grey 40 ibm grey40 netapp grey40 linux grey40 aws grey40 windows grey40 vmware grey40 citrix grey40 exchange grey40 apache grey40 oracle grey40