2 Replies Latest reply on May 1, 2008 1:26 AM by idaho51

    Monitoring virtual switches on VMWare ESX via Netflow


      Hello all,

      I have the Orion Performance Monitor and the Netflow running without any problems with my Cisco and Juniper devices.

      Today I wanted to use the Netflow on VMWare ESX to monitor the network flows and run into the following problem:

      The Netflow is running on the VMWare and it is sending to the Netflow collector (checked with sniffer), but they are discarded because I can not add the interfaces to the Orion Performance Monitor. As far as I understand Orion needs to identify the interfaces from which the Netflow packets are coming via SNMP beforehand, so it must be added via the Performance monitor. The SNMP is running on the VMWare ESX server (e.g, but the Netflow packets are marked with the IP of the VMWare kernel (, so the SNMP and the Kernel are using different addresses, and there seems to be no way to add the virtual switch interfaces to the Orion, so the Netflow is not working (just discarded at the Netflow collector).

       I hope somebody already is using VMWare netflow and Orion successfully, please help me to find a solution as we have a big need for this Netflow data.


      Best regards,

      Andreas Plaul

        • Re: Monitoring virtual switches on VMWare ESX via Netflow

          The last word that I got from our Product Manager was:

          "The ESX server’s flow support is in beta and the results are sporadic.   Our next steps are to wait till ESX officially releases flow support, and then test with NTA again."  Ref. (SolarWinds NTA PM - March 27, 2008 ) 

           When our lab manager was testing this, I don't remember him running into your scenario.  All I remember was that the actual NetFlow format coming from the ESX was not consistent.  Maybe VMWare has released a newer version since then and once you get past this issue, you can be up and running.  We would really like to see if you can get it working.

          Ok, here is what I'd do to get around your scenario:

             1. Stop the Orion NPM service

             2. In the NetPerfMon database, open the Nodes table and modify the row with an IP_Address in your example of '' to ''.  Also write down the NodeID of this row, in case you need it for step 5.

             3. Start or restart your NTA service. 

             4. Open your NTA web console and look to see now if your receiving the flow.

             5. If not receiving, but are now getting an alert indicating that the flow is coming on another interface index, open the Interfaces table in the database and look for the row (or rows) containing the NodeID that you wrote down in step 2.  Change one of those rows InterfaceIndex to the index specified in the alert.

             6. Restart your Orion NPM service.

          Hopefully that works for you.  Let us know your results.


            • Re: Monitoring virtual switches on VMWare ESX via Netflow


              first of all thanks for your answer.

              Basically I used the described approach and it works. Some things are not really, so VMWare is reporting flows from interface which are not really used by any VM, and as it can not be monitored via SNMP the status of the interfaces is "unknown".

              As the databases needs to be manually touched it is not really a scalable approach (updates, changes in the VM layout ...), therefore we decided to run a test for one week and then check whether the Netflow data reported by the ESX server is usable.

              Best regards,