# Querying the Collector TCP connection status

## Windows Collector <a href="#queryingthecollectortcpconnectionstatus-windowscollector" id="queryingthecollectortcpconnectionstatus-windowscollector"></a>

To query the status of the TCP connection between the Collector and the Nexthink instance for a particular device, run the Collector Configuration Tool on the device as follows:

`nxtcfg.exe /g tcp_status`

The Collector Configuration Tool queries the Nexthink Coordinator service, which is the [component of the Collector](broken://pages/fVII4tnl1ROWw5bdzBfQ) that is responsible for the TCP connection.

## Mac Collector <a href="#queryingthecollectortcpconnectionstatus-maccollectormac-collector" id="queryingthecollectortcpconnectionstatus-maccollectormac-collector"></a>

To query the status of the TCP connection between the Mac Collector and the Nexthink instance, open the command-line interface on your macOS device and type in:

`grep -i "tcp-status" /Library/Application\ Support/Nexthink/config.json`

## Error messages <a href="#queryingthecollectortcpconnectionstatus-errormessages" id="queryingthecollectortcpconnectionstatus-errormessages"></a>

The following table shows the possible output messages along with their description. The messages that start with a timestamp are retrieved from the Coordinator service. On the other hand, messages that start without a date come directly from the Collector Configuration Tool:

<table data-full-width="true"><thead><tr><th>Message</th><th>Definition</th></tr></thead><tbody><tr><td><strong>[ERROR] Nexthink Coordinator service is not installed</strong></td><td>The Coordinator is not found in the device. No TCP connection is established.</td></tr><tr><td><strong>[ERROR] Nexthink Coordinator service can not be queried</strong></td><td>The Coordinator is momentarily not able to respond to the query.</td></tr><tr><td><strong>[ERROR] Unknown</strong></td><td>There was an unknown error while trying to get the status of the TCP connection from the Coordinator.</td></tr><tr><td><strong>[INFO] Nexthink Coordinator service is stopped</strong></td><td>The Coordinator service is installed but not running. No TCP connection is established.</td></tr><tr><td><strong>[MM/DD/YY hh:mm:ss] [INFO] Initializing connection</strong></td><td>The Coordinator is starting and attempting to establish a TCP connection with the Nexthink instance.</td></tr><tr><td><strong>[MM/DD/YY hh:mm:ss] [INFO] Connected</strong></td><td>The Coordinator established a TCP connection with the Nexthink instance.</td></tr><tr><td><strong>[MM/DD/YY hh:mm:ss] [INFO] Disconnected</strong></td><td>The Coordinator was disconnected from the Nexthink instance and is actively waiting for a new assignment.</td></tr><tr><td><strong>[MM/DD/YY hh:mm:ss] [ERROR] Protocol failure</strong></td><td>There is a version mismatch between the Collector and the Nexthink instance.</td></tr><tr><td><strong>[MM/DD/YY hh:mm:ss] [ERROR] Customer Key issue</strong></td><td>There is a mismatch between the Customer Key in the Collector and that of the Nexthink instance.</td></tr><tr><td><strong>[MM/DD/YY hh:mm:ss] [ERROR] Certificate issue</strong></td><td><p>There is an issue with the certificate validation. Probable causes:</p><ul><li>The root CA used to sign the certificate was not deployed with the Collector installer or the root CA was not added to the Windows <em>Trusted root certification authorities</em>.</li><li>The address of the Nexthink instance that is configured in Collector does not match the address defined in the subject of the certificate.</li></ul></td></tr><tr><td><strong>[MM/DD/YY hh:mm:ss] [ERROR] Host not found</strong></td><td>The DNS name or IP address of the Nexthink instance configured in the Collector designates a host that is not found in the network.</td></tr><tr><td><strong>[MM/DD/YY hh:mm:ss] [ERROR] TCP connection failure:&#x3C;number></strong></td><td><p>Returns an</p><p><a href="https://doc.qt.io/qt-6/qabstractsocket.html#errorOccurred">error code from the underlying implementation</a> that indicates the reason for the failure.</p><p>The most common error is <em>[ERROR] TCP connection failure: 0</em>. It indicates that the host exists, but the Collector cannot connect to the indicated TCP port.</p></td></tr></tbody></table>


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.nexthink.com/platform/configuring_nexthink/bringing-data-into-your-nexthink-instance/deploying-nexthink-in-non-vdi-environment/installing-collector/managing-collector-agents/querying-the-collector-tcp-connection-status.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.