06. 10. 2015 Sandro Santinato NetEye

Netflow Analysis With Improved Nfdump Version

With the idea to get out more from the netflow data fetched by Nfdump and with special needs of our customers, we added some new and useful functionalities to make Nfdump even more interesting and useful for your network traffic analysis.

First of all, Nfdump is a collection of tools to collect and process netflow data on the command line. The netflows are typically gathered from network routers or from our nBoxes and stored on a 5 min base on the hard disk.

Min. and Max. Speed Values

The standard Nfdump version shows you the average transfer rates of a netflow. But what if you are interested in the minimum and maximum transfer rate? You would have to analyze every single transaction from a specific port to another. So, the first functionality we introduced, is the output of the minimum and maximum bit/s to the standard command line output of Nfdump (see columns min_bps and max_bps ).

Here an example command and its output:

This output shows the first ten (-n 10) flows between 24.08.2015 00:00 and 24.08.2015 04:00, indicating the values min_bps and max_bps.

Incomming, Outgoing and Internal Network Traffic

Sometimes it is very useful to analyze which is the traffic going out from your network, or coming in, or even which is the internal traffic. You may have the need to analyze how much traffic this is and how fast it is. For this purpose we introduced the new parameter -C, which lets you indicate which are your own networks. In this way, Nfdump is able to categorize your traffic and telling you, which flows are going out or coming into your network. Additionally, with the parameter -d you have the possibility to specify which traffic should be displayed, for example with -d out only the outgoing traffic is displayed (-d in shows only the incoming traffic).

Here an example output where only outgoing traffic is displayed:

This output shows the first ten (-n 10) outgoing flows (-d out) from our network (-C 10.62.4.0/24) between 24.08.2015 00:00 and 24.08.2015 04:00

Specify Times instead of Nfdump Files

The last feature we added is another new parameter, -P, which gives you the possibility to indicate times instead of the path to the Nfdump files. In this case Nfdump chooses automatically the right Nfdump files to satisfy requests in this time range.

Here a sample output where we have specified the timeperiod of 24.08.2015 from 08:00 to 09:00:

This output shows the first ten (-n 10) flows between 24.08.2015 08:00 and 24.08.2015 09:00 (-P)

Sandro Santinato

Sandro Santinato

Developer at Würth Phoenix
Hi, my name is Sandro and I am the youngest member of the Neteye team. I graduated in 2013 in Applied Computer Science at the Free University of Bolzano but I started working as software engineer at Würth-Phoenix already in May 2012. My main competence is the development and improvement of the “Real User Experience” solution.For me computer programming is not just work, but i like scripting and creating my own software also in my free time. Already as a child I was amazed by computers and their technology. So at the age of 12 I bought the book “C for dummies” and started learning programming on my own 🙂 Later on I discovered the open-source world and I started loving it from the first moment.In my free time I also like mountain biking, hiking, and of course playing the trombone in various music bands.

Author

Sandro Santinato

Hi, my name is Sandro and I am the youngest member of the Neteye team. I graduated in 2013 in Applied Computer Science at the Free University of Bolzano but I started working as software engineer at Würth-Phoenix already in May 2012. My main competence is the development and improvement of the “Real User Experience” solution.For me computer programming is not just work, but i like scripting and creating my own software also in my free time. Already as a child I was amazed by computers and their technology. So at the age of 12 I bought the book “C for dummies” and started learning programming on my own :-) Later on I discovered the open-source world and I started loving it from the first moment.In my free time I also like mountain biking, hiking, and of course playing the trombone in various music bands.

4 Replies to “Netflow Analysis With Improved Nfdump Version”

  1. LUCIANO MARTINS says:

    Hello. I’m interested in this modified version of NFDUMP, because I need to know MAX and MIN of my flows.

    Could you help me? Is it possible to deliver this nfdump version?

    Regards,
    Luciano

    1. Julia Helfer says:

      Hi Luciano,
      we implemented this feature on request of one of our customers and made it available for download to all NetEye customers within the official NetEye repository.

      We modified the function PrintStatLine in the file nfstat.c in order to get the min and max values. To get the values we’ve added the values min_bps and max_bps

      Regards,
      Julia

  2. faisal says:

    hello
    could I have contact with Sandro for an important thing

    1. Julia Helfer says:

      Hi Faisal,

      sure, you can write an email to neteye@wuerth-phoenix.com
      It would be nice if you could share your request also here on our blog, in this way, other readers who maybe have similar questions can also read it.

      Regards,
      Julia

Leave a Reply

Your email address will not be published.

Archive