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Certificate expiry error

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We set up the SSL Certificate Sensor on an web server vectorneighbourhood.co.nz. It reported correctly the certificate was expiring and we have since renewed the certificate. The website now reports correctly that our certificate expires on 16/12/2020. The sensor is still telling us there's 9 days until the certificate expires. Thinking this might then be something that's cached, we have added the sensor to a brand new installation of PRTG on a demo server environment. This new install tells us there's 9 days for the certificate to expire ... where is this information coming from?? Why doesn't it pick up the new certificate information?? It's the same issue olas had in August.

prtg-network-monitor ssl-certificate sslcertexpiration

Created on Jan 15, 2020 10:05:00 PM



5 Replies

Votes:

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Hi there,

If the target URL is a virtual host hosting multiple sites, a wrong SNI might be the culprit here. Is there any chance that this is misconfigured in the settings of the sensor? To see what an SNI does, kindly take a look here.

Kind regards,
Felix Saure, Tech Support Team

Created on Jan 16, 2020 12:13:30 PM by Felix Saure [Paessler Support]



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Hi Felix, Thanks for your reply.

So if, in a browser, I type in www.vectorneighbourhood.co.nz, it takes me to https://vectorneighbourhood.co.nz. So I've tried configuring www.vectorneighbourhood.co.nz as well as vectorneighbourhood.co.nz as the SNI. Nothing makes any difference.

Grant

Created on Jan 16, 2020 7:17:16 PM



Votes:

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Hi Grant,

Thanks for your reply! Please enable the
Write sensor result to disk (Filename: "Result of Sensor [ID].txt"
and forward the resulting text files. They are located on the probe host in the directory

"C:\ProgramData\Paessler\PRTG Network Monitor\Logs (Sensors)".

Kind regards,
Felix Saure, Tech Support Team

Created on Jan 17, 2020 10:01:45 AM by Felix Saure [Paessler Support]



Votes:

0

Hi,

I'm also having this issue

The thumbprint reported in PRTG is not the same as the current https cert thumbprint (maybe it's the old cert?)

we do not use a proxy for this sensor

Created on Dec 28, 2020 2:54:45 PM



Votes:

0

Hello there,

First, I would ask you to check if the SNI is configured correctly here. If the issue still persists, I would ask you to activate to write the sensor results and provide us with those in a support case.

That way we can assist in an easier way.

Kind regards,
Birk Guttmann, Tech Support Team

Created on Dec 29, 2020 8:07:01 AM by Birk Guttmann [Paessler Support]




Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.