Historical Flows

ntopng can dump flows data to a persistent storage and provides view to browse recorded flows data in the past.

Traditionally, in order to provide historical data, ntopng required a connected MySQL database. Check out the Flows Dump documentation for more details on how to setup the connection and the historical views available for this mode.

However, due to the users feedback on the MySQL low performance with high flow insertion rates, ntopng now integrates a specialized flows dump database called nIndex which overcomes the limits of MySQL. This is currently available only in the enterprise version of ntopng for Linux/x86_64 architectures.


The historical views provided with the MySQL integration (like the “Historical Explorer”) are not compatible with nIndex.


nIndex is only available on Linux/x86_64 architectures.

The rest of this page documents the use of nIndex as flows storage.

Enabling Flow Dump

In order to dump flows to disk ntopng requires the -F nindex option to be specified as described in the Flows Dump documentation. After this is enabled, new “Flows” entries will appear into the historical charts tabular view dropdown:

Historical Charts dropdown with flows

Browsing Flows

Historical flows data can be accessed from the Historical Charts and are contextual for the specified time frame.

Historical Flows Top L7 Contacts

Here is an overview of the currently available flows views:

  • Top Clients: shows the top hosts as flow clients and their traffic as flow clients
  • Top Servers: shows the top hosts as flow servers and their traffic as flow servers
  • Top L7 Contacts: shows the top <client, server, L7 protocol> pairs and their total traffic

By clicking on the drilldown_icon icon, it’s possible to explode a particular communication or host and analyze the raw flows.

Raw Flows

The picture above, for example, shows the raw flows between PC local and having the AppleiCloud protocol.

Exporting Flows

By clicking on the flow_export_icon icon, it’s possible to download a copy of the raw flows in CSV format. Here is the same data shown in the picture above in CSV format:

143|443|1544712866|18262|1544712646|1544712866|32886|PC local|4|||53||1|ssl|feedbackws.icloud.com|::|0|6|::
143|443|1544712876|13958|1544712749|1544712876|34078|PC local|4|||46||1|ssl|p66-iwmb0.icloud.com|::|0|6|::
143|443|1544718548|203978|1544718247|1544718548|38928|PC local|4|||431||1|ssl|p66-ckdatabasews.icloud.com|::|0|6|::
143|443|1544718821|175770|1544718548|1544718821|38928|PC local|4|||370||1|ssl|p66-ckdatabasews.icloud.com|::|0|6|::
143|443|1544723738|14663|1544723557|1544723738|49328|PC local|4|||45||1|ssl|p66-pushws.icloud.com|::|0|6|::

Data Retention

The retention of the flows dump on disk can be configured from the Data Retention setting.