This article applies as of PRTG 20.1.55

Reasons for the change

In PRTG versions prior to 20.1.55, we did not validate a probe’s global identifier (GID). As a result, the Probe GID you could manually assign to a remote probe or a mini probe via the PRTG Administration Tool could be any string, for example, {johnqpublic-company}.

As of PRTG 20.1.55, GIDs like {johnqpublic-company} are invalid. The GIDs must have the correct format to make probe connections more reliable. A valid GID can have one of the following formats:

• {3D1E94F6-6481-4B75-B3F5-A669EE98DA6F}
• 3D1E94F6-6481-4B75-B3F5-A669EE98DA6F

If you manually changed a remote probe’s GID to a string like {johnqpublic-company}, PRTG automatically generates a new, valid GID for the remote probe the next time it connects to the PRTG core server.
Therefore, the change does not affect your remote probe configuration and monitoring setup. You can continue your monitoring as usual.

If you manually changed a mini probe’s GID to a string like {johnqpublic-company}, you need to manually update the invalid GID to a valid GID in the correct format. Otherwise, the mini probe will no longer be able to connect to the PRTG core server because it cannot update automatically.

Additional changes

We also implemented some changes to the functionalities of the PRTG Administration Tool:

• It is still possible to edit a probe GID using the PRTG Administration Tool. However, you can no longer assign an invalid GID to a probe. Entering an invalid GID results in an error message and the previous, valid GID is restored.
• We added a Generate new GID… button on the Probe Settings for Core Connection tab.

Important notice: Generating a new probe GID is a critical action. It will cause the remote probe or the mini probe, for example, to be detected as a new probe the next time it connects to the PRTG core server. As a result, you have to approve the probe again. Furthermore, if you wish to continue monitoring your network with the same device and sensor setup as before, you need to manually move your monitoring objects to the new probe.

Keep in mind that this also applies when downgrading to a PRTG version prior to 20.1.55. When you use a previous probe configuration that still contains the former probe GIDs, PRTG detects remote probes or mini probes as new probes the next time they connect to the PRTG core server.