When you are looking to track down a host using your Cisco NetFlow reporting tool, sometimes it helps to consider Source or Destination. What I mean by this is are you looking for the host creating the traffic or receiving the traffic?

Below are the top Internet hosts we are receiving traffic from on our T-1 for the last 5 minutes. Notice: Inbound & Src.

netflow source and destination

I want to know who is sending data to the host I click on the Search tool in Scrutinizer and enter the IP address.

netflow source and destination

Notice above that since I searched all the routers and switches sending NetFlow or sFlow it found the host on four different pieces of equipment.

PLXSW3 is an sFlow switch on the periphery of our network. I’m looking for the Source host sending data to the Destination Above, I selected the Dst report. Basically, I want an sFlow analysis report, showing me the Sources sending data to the Destination of

Below, I drilled in for details and did some network traffic analysis. I know we blog a lot about NetFlow, but sFlow ROCKS as well.

netflow source and destination

Above, you can see that mixmastermitch’s PC (i.e. the Source) is sending the data to the Destination I also know that Mitch is plugged in on port 2. Should we turn his port off?


Mike Patterson author pic


Michael is one of the Co-founders and the former product manager for Scrutinizer. He enjoys many outdoor winter sports and often takes videos when he is snowmobiling, ice fishing or sledding with his kids. Cold weather and lots of snow make the best winters as far as he is concerned. Prior to starting Somix and Plixer, Mike worked in technical support at Cabletron Systems, acquired his Novell CNE and then moved to the training department for a few years. While in training he finished his Masters in Computer Information Systems from Southern New Hampshire University and then left technical training to pursue a new skill set in Professional Services. In 1998 he left the 'Tron' to start Somix which later became Plixer.


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