In general, ‘Connection Refused’ error occurs when a connection to the Virtual DataPort server fails with following reasons such as host unreachable, incorrect port, etc.
In order to resolve this issue, you could check the following steps:
* You could check if you are able to ping the Virtual DataPort server from the location of the Virtual DataPort Administration Tool which you are using.
* Check the configuration of the RMI Host settings in the Denodo Platform Control Center. You could refer to the Knowledge Base article [RMI host configuration](https://community.denodo.com/kb/en/view/document/RMI%20host%20configuration) for more information.
* Ensure the firewall settings to make sure you have the access to connect.
* If you are using the Virtual DataPort Administration Tool on the server, but not on remote machines, you could review your [Remote connectivity configuration](https://community.denodo.com/kb/en/view/document/Remote%20connectivity%20configuration) and try modifying the value of the RMI host tab.
* Also, check the vdp.log located under ‘<DENODO_HOME>/logs/vdp’ folder for detailed errors.
You could refer to a similar community - [Q&A](https://community.denodo.com/answers/question/details?questionId=9064u000000L860AAC&title=Denodo+Virtual+DataPort+Server+does+not+start+From+Denodo+Platform+Control+Center%3B+Data+Catalog%2C+Web+Design+Studio+and+Diagnostic+%26+Monitor+Do+Start) for more details on this error Connection Refused.
Hope this helps!