<%NUMBERING1%>.<%NUMBERING2%>.<%NUMBERING3%> PRTG Manual: Install a Remote Probe

Remote probes can extend your monitoring with PRTG.

• With remote probes, you can monitor different subnetworks that are separated from your PRTG core server by a firewall, and you can keep an eye on remote locations. You can install one or more remote probes.
• Remote probes are useful if you want to distribute monitoring load by taking it from the PRTG core server system and putting it on one or more remote probe systems.
• You need a remote probe if you want to monitor your local network with a PRTG Hosted Monitor instance.

PRTG automatically updates remote probes but, in rare cases, you must manually update remote probes. You receive a ToDo ticket in this case. Follow the steps below to manually update remote probes.

If you run PRTG in a cluster, see Cluster and Remote Probes Outside the LAN in this section.

If you have issues after the installation, see section Debugging Remote Probe Connection Issues.

For a partially automatic installation of a remote probe directly from the device tree in the PRTG web interface, see section Remote Probe Setup via Device Tools. For a quick installation guide, see the Paessler website: How to install a PRTG remote probe in 4 steps.

Steps to Take

To install a remote probe with the Remote Probe Installer, follow these steps:

• Step 1: Meet the Requirements
• Step 2: Prepare the PRTG Core Server: start here if you use PRTG Network Monitor
• Step 3: Download the Remote Probe Installer from the PRTG Web Interface: start here if you use PRTG Hosted Monitor
• Step 4: Install a New Remote Probe
• Step 5: Approve the New Remote Probe

Step 1: Meet the Requirements

To install a remote probe on a target system, make sure that you meet the following requirements.

• The target system runs on at least Windows 7.
• The target system is accessible via remote procedure call (RPC). This is usually the case when your PRTG core server and the target system are located in the same LAN segment. Otherwise, open Windows services.msc on the target system and start the RPC service.
• Programs are allowed to communicate through your Windows Firewall. Open the settings of your firewall and select Allow an app through firewall. Mark the check box for Remote Service Management, and the check box Public in the corresponding line.

• Because the probe initiates the connection, you must make sure that a connection to your PRTG core server from the outside can be established. The process is the same as if you wanted to allow access to the PRTG web server provided by the PRTG core server via port 80 or 443. In most cases, this means that you will require an allow or allow-nat network address translation (NAT) rule that enables the probe to reach the PRTG core server via the Transmission Control Protocol (TCP) port 23560. Then, the probe uses a dynamic port from the high port range (49152 - 65535) for outgoing connections.

If you need to set a different port, which we do not recommend, see the Knowledge Base: How can I customize ports for core-probe connections used by PRTG?

PRTG Network Monitor and PRTG Hosted Monitor already include a local probe or hosted probe on the PRTG core server. This is why you cannot additionally install a remote probe on your PRTG core server system.

For more information on the requirements for remote probes, see section System Requirements.

Step 2: Prepare the PRTG Core Server

If you use PRTG Hosted Monitor, you can start with Step 3: Download the Remote Probe Installer from the PRTG Web Interface right away.

Because your remote probe needs to connect to your PRTG core server, PRTG needs to accept incoming remote probe connections. So, with PRTG Network Monitor, first prepare your PRTG core server before you install the remote probe.

Edit the relevant settings in section Core & Probes. From the main menu in the PRTG web interface, select Setup | System Administration | Core & Probes to access the probe settings and go to the Probe Connection Settings.

Step 2.1: Probe Connection IP Addresses

By default, a PRTG core server accepts connections from the local probe only (IP address 127.0.0.1). This setting is the most secure setting, but it does not allow any remote probes to connect to your PRTG core server.

To accept remote probes, select one of the following settings:

• All IP addresses available on this computer: Any IP address on your PRTG core server system accepts incoming probe connections.
• Specify IP addresses: Specify IP addresses that accept incoming connections.

Step 2.2: Allow IP Addresses

In the Allow IP Addresses field, you can enter the IP address of the target system on which you want to install a remote probe. You can also enter the word any. This sets the PRTG core server to accept remote probe connections from any IP address.

If you use any, make sure that you only write the word in lower case. Other variations are not valid.

Other settings are not required. For more information about the fields for Access Keys, Deny IP Addresses, and Deny GIDs, see section Core & Probes.

When you are done, click Save to save your settings.

If you change this setting, PRTG needs to restart the PRTG core server to apply your changes. After you click Save, a dialog box appears that asks you to confirm the restart. Click OK to trigger the restart. During the restart, all users of the PRTG web interface, the PRTG app for desktop, or the PRTG Apps for Mobile Network Monitoring are disconnected and reconnected.

To edit the core–probe connection settings, you can also use the PRTG Administration Tool on your PRTG core server.

Cluster and Remote Probes Outside the LAN

If you run PRTG as a cluster and you want to run remote probes outside your local network, you must make sure that your cluster nodes and the addresses that they use are reachable from the outside. Check your cluster node settings under Cluster before you install a remote probe outside your local network. Enter valid Domain Name System (DNS) names or IP addresses for both cluster nodes to reach each other and for remote probes to individually reach all cluster nodes. Remote probes outside your LAN cannot connect to your cluster nodes if they use local addresses.

If you already have a remote probe installed outside your LAN and the remote probe is disconnected because of this, follow these steps:

1. Uninstall the remote probe.
2. Update the cluster node settings with addresses that are reachable from outside your LAN.
3. Restart the PRTG core servers.
4. Install the remote probe again. It then obtains the IP address or DNS name entries that it can reach.

See also section Failover Cluster Configuration, section Remote Probes in a Cluster.

Step 3: Download the Remote Probe Installer from the PRTG Web Interface

1. On the computer on which you want to install a remote probe, log in to the PRTG web interface.
2. From the main menu bar, select Setup | Optional Downloads | Remote Probe Installer.
3. Click Add Remote Probe to start the installation assistant.
   The Add Remote Probe button is also available in the device tree.
4. Wait until the installation is completed. The remote probe then automatically connects to your PRTG core server.
5. In the appearing dialog window, click Prepare and Download to start the download.
6. Save the setup program to your local disk.

In the installation approach with the assistant, PRTG guides you through the installation process. If you Download the Remote Probe Installer directly, you must install the remote probe without the assistant.

If you connect your remote probe to PRTG Network Monitor, prepare your Probe Connection Settings first.

The PRTG version numbers of the PRTG core server service and PRTG probe service must match. PRTG automatically updates remote probes when you install a new version on the PRTG core server. If PRTG advises you to manually update your remote probe, open a web browser on the remote computer and download the remote probe installer as described in this section.

Step 4: Install a New Remote Probe

1. Execute the setup program that you downloaded.
2. Confirm the Windows User Account Control dialog with Yes to allow the installation. The usual software installation wizard guides you through the installation process.
3. Click Install to start the installation process.

Wait until the installation is complete. The remote probe then automatically connects to your PRTG core server.

If the remote probe successfully connects to your PRTG core server, you can complete the setup of your new remote probe.

To allow your new remote probe to connect to a PRTG Hosted Monitor instance, PRTG automatically sets the Allow IP Addresses field in Core & Probes to any. You can also use any for PRTG Network Monitor, but we recommend that you use this setting in intranets only. If any is not an option for you, cancel it in the Allow IP Addresses field and enter the IP address of your remote probe instead.

4. Click Continue to finish the remote probe installation.

5. Click Finish to exit the installation wizard.

The remote probe is now installed on your computer as a Windows service.

Step 5: Approve the New Remote Probe

In the installation assistant, click Installation Done.

If you successfully installed the remote probe from a PRTG Hosted Monitor installation, you see the following dialog box.

Click Approve and auto-discover to include the new remote probe and network in your device tree and to start the auto-discovery. It discovers devices and automatically creates suitable sensors. Optionally, click Approve to only approve the remote probe without the auto-discovery. The remote probe appears in your device tree.

For unwanted remote probe connections, click Cancel. A new window appears in the lower-right corner.

Click Deny to deny the new remote probe.

If you deny or remove a remote probe, PRTG automatically adds the global ID (GID) of this device to the Deny GIDs list in Core & Probes. PRTG automatically denies future remote probe connections from this device.

If you deny the remote probe in the device tree, it does not uninstall the remote probe, but only denies access to the PRTG core server. The remote probe continues to run on the target system until you uninstall it manually.

Once approved, PRTG automatically opens the new remote probe in the device tree and creates a set of sensors for the remote probe to make sure you can immediately detect bottlenecks on the remote probe system. We recommend that you keep these sensors. You can now create groups, devices, and sensors for monitoring via the new remote probe.

You do not need to approve remote probes after updates.

When a new remote probe connects to the PRTG core server for the first time, you receive a new ToDo ticket.

Debugging Remote Probe Connection Issues

If you have issues with the connection between the PRTG core server and remote probe, make sure that you meet the following requirements:

• Recheck if you fulfilled all the requirements as described in step 1 of this section like the Windows Firewall settings.

• The IP address of the computer on which you want to install a remote probe is not listed in the Deny IP Addresses field in Core & Probes.

• You can also take a look at the log files of the remote probe. The probe process writes log files with a file name in the format PRTG Probe Log (x).log. Open the one with the most recent date.

For a correct connection, the log should look similar to this:

11/6/2023 1:21:58 PM PRTG Probe V23.4.90.1235
11/6/2023 1:21:58 PM System time zone: (UTC+01:00) Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna
11/6/2023 1:21:58 PM libeay32.dll=1.0.2.11
11/6/2023 1:21:58 PM ssleay32.dll=1.0.2.11
11/6/2023 1:21:58 PM PRTG Probe "example-DNS" starting on "example-DNS" (GID={AAAA1111-22BB-33CC-DD44-EEEEEE555555})
11/6/2023 1:21:58 PM Memory Manager: NexusMM4
11/6/2023 1:21:58 PM OS: Microsoft Windows 10 Enterprise (10.0 Build 15063), 4 CPUs (Quad x64 Model 78 Step 3), code page "Windows-1252", on "NVME SAMSUNG MZFLV256"
11/6/2023 1:21:58 PM Data Path: C:\ProgramData\Paessler\PRTG Network Monitor\
11/6/2023 1:21:58 PM System Path: C:\Program Files (x86)\PRTG Network Monitor\
11/6/2023 1:21:58 PM Local IP: 0.0.0.0
11/6/2023 1:21:58 PM Core Server IP: example-DNS.exampledomain.com
11/6/2023 1:21:58 PM Core Server Port: 23560
11/6/2023 1:21:58 PM SSL Enabled
11/6/2023 1:21:58 PM Probe GID: {AAAA1111-22BB-33CC-DD44-EEEEEE555555}
[...]
11/6/2023 1:21:58 PM Start Connection
11/6/2023 1:21:58 PM Start Done
11/6/2023 1:21:58 PM (14608):Initializing WMIConnectionPool
11/6/2023 1:21:58 PM (14608):WMIConnectionPool maximum number of concurrent establishings is set to: 20
11/6/2023 1:22:03 PM Connect from to example-DNS.exampledomain.com:23560
11/6/2023 1:22:03 PM TCP connected from 10.49.12.51:55199 to example-DNS.exampledomain.com:23560
11/6/2023 1:22:03 PM State changed to connected (example-DNS.exampledomain.com:23560)
11/6/2023 1:22:03 PM Reconnect
11/6/2023 1:22:04 PM Connected
11/6/2023 1:22:10 PM Send Login
11/6/2023 1:22:10 PM Local: 11/6/2023 1:22:10 PM UTC: 11/6/2023 12:22:10 PM
11/6/2023 1:22:10 PM MarkUnused
11/6/2023 1:22:10 PM Login OK: Welcome to PRTG

If the connection fails, for example because of an incorrect Access Key, or because of incorrect IP address settings (see step 2), you see:

11/6/2023 1:42:02 PM Try to connect...
11/6/2023 1:42:02 PM Connected to 10.0.2.167:23560
11/6/2023 1:42:07 PM Login NOT OK: Access key not correct!

If you need to adjust any settings for the connection to the PRTG core server, use the PRTG Administration Tool on the remote probe system.

Under Connection to PRTG Core Server, you can then edit the following settings:

• Server (IPv4 Address or DNS Name): Enter the IP address or Domain Name System (DNS) name of the PRTG core server that the remote probe is to connect to. If you use network address translation (NAT) rules, you must enter the IP address that is externally visible, because the remote probe connects from outside your network.
• Access Key and Confirm Access Key: Enter the access key that the remote probe is to send to the PRTG core server. You must define this access key on the PRTG core server in Core & Probes. Make sure that the access keys match.

Click Save & Close to confirm your settings and to (re)start the PRTG probe service.

For more information about these settings, see section PRTG Administration Tool.

More

KNOWLEDGE BASE

How can I customize ports for core-probe connections used by PRTG?

• https://kb.paessler.com/en/topic/65084

I cannot open the PRTG web interface via the desktop shortcut anymore. What can I do?

• https://kb.paessler.com/en/topic/89024

PAESSLER WEBSITE

How to connect PRTG through a firewall in 4 steps

• https://www.paessler.com/support/how-to/firewall

How to install a PRTG remote probe in 4 steps

• https://www.paessler.com/support/how-to/remote-probe-installation