Configure ntopng to receive JA4C data

Oct 13, 2025 by wbrum.org 31 views

Introduction

ntopng is a powerful network traffic analysis tool that provides real-time insights into network activity. One of the key features of ntopng is its ability to collect and display various types of network traffic data, including JA4C (JSON-based Application Flow) data. In this article, we will explore the process of adding JA4 collection in ntopng, including collecting JA4C sent from nprobe and cento, displaying it in the web GUI, dumping JA4 in ClickHouse, and creating a mini dashboard to display top JA4C hashes.

Collecting JA4C Sent from nprobe and cento

To collect JA4C sent from nprobe and cento, we need to configure ntopng to receive and process this data. Here are the steps to follow:

Configure ntopng to receive JA4C data: In the ntopng configuration file (usually located at /etc/ntopng/ntopng.conf), add the following lines to enable JA4C data collection:

[JA4]
enabled = true

This will enable JA4C data collection in ntopng.

Configure nprobe and cento to send JA4C data: In the nprobe and cento configuration files, add the following lines to enable JA4C data sending:

[JA4]
enabled = true

This will enable JA4C data sending from nprobe and cento to ntopng.

Verify JA4C data collection: After configuring ntopng, nprobe, and cento, verify that JA4C data is being collected by checking the ntopng logs. You should see entries indicating that JA4C data is being received and processed.

Displaying JA4 in the Web GUI

To display JA4 in the web GUI, we need to modify the ntopng web interface to include JA4-related information. Here are the steps to follow:

Modify the ntopng web interface: In the ntopng web interface, add a new page to display JA4-related information. This can be done by modifying the index.html file in the ntopng web interface directory (usually located at /usr/share/ntopng/web).
Add JA4-related information: In the modified index.html file, add the following code to display JA4-related information:

<div class="ja4-container">
  <h2>JA4 Data</h2>
  <table>
    <tr>
      <th>Hash</th>
      <th>Count</th>
    </tr>
    <tr ng-repeat="ja4 in ja4s">
      <td>{{ ja4.hash }}</td>
      <td>{{ ja4.count }}</td>
    </tr>
  </table>
</div>

This code will display a table with JA4 hashes and their corresponding counts.

Verify JA4 display: After modifying the ntopng web interface, verify that JA4 data is being displayed correctly. You should see a table with JA4 hashes and their corresponding counts.

Dumping JA4 in ClickHouse

To dump JA4 in ClickHouse, we need to configure ntopng to send JA4 data to ClickHouse. Here are the steps to follow:

Configure ntopng to send JA4 data to ClickHouse: In the ntopng configuration file, add the following lines to enable JA4 data sending to ClickHouse:

[JA4]
enabled = true
clickhouse = {
  host = "localhost"
  port = 9000
  database = "ja4"
  table = "ja4_data"
}

This will enable JA4 data sending to ClickHouse.

Verify JA4 data dumping: After configuring ntopng, verify that JA4 data is being dumped correctly in ClickHouse. You should see entries in the ClickHouse database indicating that JA4 data is being received and processed.

Creating a Mini Dashboard for JA4C Hashes

To create a mini dashboard for JA4C hashes, we need to modify the ntopng web interface to include a new page with JA4-related information. Here are the steps to follow:

Modify the ntopng web interface: In the ntopng web interface, add a new page to display JA4-related information. This can be done by modifying the index.html file in the ntopng web interface directory (usually located at /usr/share/ntopng/web).
Add JA4-related information: In the modified index.html file, add the following code to display JA4-related information:

<div class="ja4-dashboard">
  <h2>JA4 Dashboard</h2>
  <div class="ja4-hash-container">
    <h3>Top JA4C Hashes Originating from Local Network</h3>
    <table>
      <tr>
        <th>Hash</th>
        <th>Count</th>
      </tr>
      <tr ng-repeat="ja4 in ja4s">
        <td>{{ ja4.hash }}</td>
        <td>{{ ja4.count }}</td>
      </tr>
    </table>
  </div>
  <div class="ja4-hash-container">
    <h3>Top JA4C Hashes Hitting Local Network</h3>
    <table>
      <tr>
        <th>Hash</th>
        <th>Count</th>
      </tr>
      <tr ng-repeat="ja4 in ja4s">
        <td>{{ ja4.hash }}</td>
        <td>{{ ja4.count }}</td>
      </tr>
    </table>
  </div>
</div>

This code will display two tables with top JA4C hashes originating from the local network and those hitting the local network.

Verify JA4 dashboard: After modifying the ntopng web interface, verify that the JA4 dashboard is being displayed correctly. You should see two tables with top JA4C hashes.

Conclusion

Q: What is JA4 and why is it important for network traffic analysis?

A: JA4 (JSON-based Application Flow) is a data format used to represent network traffic flows. It provides detailed information about network activity, including source and destination IP addresses, ports, protocols, and more. JA4 is important for network traffic analysis because it allows for more accurate and detailed insights into network behavior.

Q: How do I configure ntopng to collect JA4C sent from nprobe and cento?

A: To configure ntopng to collect JA4C sent from nprobe and cento, you need to add the following lines to the ntopng configuration file:

[JA4]
enabled = true

You also need to configure nprobe and cento to send JA4C data to ntopng.

Q: How do I display JA4 in the web GUI?

A: To display JA4 in the web GUI, you need to modify the ntopng web interface to include JA4-related information. You can do this by modifying the index.html file in the ntopng web interface directory (usually located at /usr/share/ntopng/web).

Q: How do I dump JA4 in ClickHouse?

A: To dump JA4 in ClickHouse, you need to configure ntopng to send JA4 data to ClickHouse. You can do this by adding the following lines to the ntopng configuration file:

[JA4]
enabled = true
clickhouse = {
  host = "localhost"
  port = 9000
  database = "ja4"
  table = "ja4_data"
}

Q: How do I create a mini dashboard for JA4C hashes?

A: To create a mini dashboard for JA4C hashes, you need to modify the ntopng web interface to include a new page with JA4-related information. You can do this by modifying the index.html file in the ntopng web interface directory (usually located at /usr/share/ntopng/web).

Q: What are the benefits of adding JA4 collection in ntopng?

A: The benefits of adding JA4 collection in ntopng include:

More accurate and detailed insights into network behavior
Improved network traffic analysis capabilities
Enhanced security and threat detection
Better network performance optimization

Q: Are there any limitations or challenges associated with adding JA4 collection in ntopng?

A: Yes, there are several limitations and challenges associated with adding JA4 collection in ntopng, including:

Increased system resources required for JA4 data processing
Potential performance impact on ntopng
Complexity of JA4 data processing and analysis
Limited support for certain network protocols or devices

Q: How do I troubleshoot issues related to JA4 collection in ntopng?

A: To troubleshoot issues related to JA4 collection in ntopng, you can:

Check the ntopng logs for errors or warnings related to JA4 data processing
Verify that JA4 data is being sent from nprobe and cento to ntopng
Check the ntopng configuration file for correct JA4 settings
Consult the ntopng documentation or seek support from the ntopng community

Q: Can I customize the JA4 dashboard to meet my specific needs?

A: Yes, you can customize the JA4 dashboard to meet your specific needs by modifying the ntopng web interface to include additional JA4-related information or by creating custom dashboards using ntopng's API.