Hi I've been setting up some SSL Certificates sensors for mutliple servers, on a few on them I've gotten the following error response. 

Failed to establish secure connection 
[Step 0] Socket Error # 11001 Host not found. 
[Step 1] Socket Error # 11001 Host not found. 
[Step 2] Socket Error # 11001 Host not found. 
[Step 3] Socket Error # 11001 Host not found. 
[Step 4] Socket Error # 11001 Host not found. 
[Step 5] Socket Error # 11001 Host not found.

I've tried searching around but I haven't been able to find an answer for this. Is it possible that PRTG is being blocked by these servers firewalls?

Article Comments

Hi there,

Is the site available when opening it in a browser on the PRTG server? No typos in the device address?

Kind regards,
Stephan Linke, Tech Support Team


Nov, 2017 - Permalink

Yes all sites are available when trying to access them via Internet Explorer, No there isn't any typo's in the device address's


Nov, 2017 - Permalink

Hi there,

Are the pages available publicly so I could test them within my local installation?

Kind regards,
Stephan Linke, Tech Support Team


Nov, 2017 - Permalink

Yes the pages are available:

  1. https://mcia-crm.co.uk
  2. https://booking.bikesafe.co.uk/
  3. https://aircraftit.com/MRO/Index.aspx
  4. https://aircraftit.com/

Nov, 2017 - Permalink

Well, they're working for me, although only support SSL up to v3.

Are you using a proxy within your network by any chance that is not yet configured in PRTG under Setup | System Administration | Core & Probes | Proxy Configuration? Note that the proxy might be configured via GPO and not be visible in the IE settings in case you checked that already.

Kind regards,
Stephan Linke, Tech Support Team


Nov, 2017 - Permalink