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Error connecting with SSL. EOF was observed that violates the protocol



Last week one of our switches all of a sudden got an alert on its HTTP sensor stating:

Error connecting with SSL. EOF was observed that violates the protocol

After restarting the switch, sensor went back to status OK. 4 days later, the problem reoccured.

Sensor has been running fine since we've implemented PRTG about 3 months ago. No changes were made to the switch's configuration or work load. (The switch doesn't even have any devices attached to it, as it is our backup switch)

HTTP sensor settings are:

  • Timeout (Sec.): 60
  • URL: https:///
  • Request Method: GET
  • SSL Method: SSL V2 or V3

What is causing this error? How do we resolve it.

Many thanks and congratulations to the entire PRTG team. You guys made an awesome piece of software!

eof http ssl

Created on Jul 9, 2013 10:10:49 AM

1 Reply



Have you checked that it is not a key length issue? New browser (and MS) security requirements enforce SSL certificates be a minimum 1024-bit key in length.

If you cannot configure/request the server meed this minimum, consider the following workaround for bypassing on the client side: http://support.microsoft.com/kb/2661254

From an admin command prompt, execute: certutil -setreg chain\minRSAPubKeyBitLength 512

Created on Oct 24, 2013 4:37:09 PM

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.