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Monitoring VMware ESXi 5.5 does not work. What can I do?



When I try to monitor vSphere Hypervisor (ESXi) version 5.1 or higher, an error occurs and monitoring VMware does not work. The error message says The underlying connection was closed: An unexpected error occurred on a send. Is this a known issue? What can I do?

error esxi prtg vmware vsphere windows-2003 windows-server-2003 windows-xp

Created on Oct 8, 2013 12:39:28 PM by  Gerald Schoch [Paessler Support]

Last change on May 20, 2019 8:49:40 AM by  Maike Guba [Paessler Support] (2,404) 2 1

2 Replies

Accepted Answer



This article applies as of PRTG 22

Monitoring ESXi 5.1 and higher: Handshake failure on Windows XP/Server 2003

vSphere Client 5.1 and higher only accepts connections that use strong cipher suites. Since Windows XP and Windows Server 2003 do not use these, the client cannot connect to the server due to a handshake failure.

For the same reason, you may encounter similar problems if your probe runs on Windows XP or Windows Server 2003 and you want to monitor ESXi 5.1 or higher via SOAP sensors.

Note: Running PRTG on Windows XP or Windows Server 2003 is not officially supported.

For details about this handshake failure and possible workarounds, refer to the VMware Knowledge Base:

Created on Oct 8, 2013 12:42:34 PM by  Gerald Schoch [Paessler Support]

Last change on Jan 3, 2023 9:39:38 AM by  Brandy Greger [Paessler Support]



Very helpful every time I upgrade a vmware host to esxi 5.5 when running prtg on a win2k3 probe. Thank you.

Created on Mar 19, 2015 3:18:27 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.