SEMblog

I was recently asked to look at an Exchange server giving the common PowerShell connection failure due to Kerberos authentication. 

The following error occurred while attempting to connect to the specified Exchange server 'rpi-exchange.rp.local':

"The attempt to connect to http://rpi-exchange.rp.local/PowerShell using "Kerberos" authentication failed: Connecting to the remote server failed with the following error message: The connection to the specified remote host was refused. Verify that the WS-Management service is running on the remote host and configured to listen for requests on the correct port and HTTP URL. For more information, see the about_Remote_Troubleshooting Help topic. "

The usual reasons for this error are well documented and I am not covering them here. After spending an hour going through the usual suspects, I started to look for anything else, as this was giving a Connection Refused error, which wasn't hugely documented past the Remote PowerShell permission. 

I then had a brainwave. I was working on a system in a school. Schools have pretty restricted Internet access in most cases. This usually means a proxy. 

Netsh winhttp show proxy 

That command immediately showed there was a proxy, running

Netsh winhttp reset proxy

Cleared the proxy settings and allowed the Exchange Management Console to start correctly. 

The client was then advised to check their proxy configuration settings, specifically the exceptions list so that the correct ones were in place, as I feared that next time Group Policy applied the proxy settings, the change would be reset.