AnsweredAssumed Answered

Network Control Module sFlow Target

Question asked by metrostar on Jul 1, 2016
Latest reply on Jul 4, 2016 by

Hey all,


I'm trying to get the Network Control Module configured using an sFlow target and not having much success. I am currently using PRTG and have configured one of our Force10 S4810P switches to send flow data to PRTG. All of that is working perfectly and I can see sFlow data in PRTG. However I cannot get VMTurbo to connect to PRTG to pull the data. The target validation takes a very long time and finally fails with a generic validation failed message. I tried turning the Windows Firewall off on the VM running PRTG and when I do that and try to validate the target I immediately get a connection refused error. I looked in the catalina.out log file and these are the types of errors I'm seeing:


The following exception occurred while attempting to connect to Connection Refused


Problem trying to open ssh connection to host: There was a problem while connecting to


Exception while creating a session with NetFlow Target java.lang.IllegalStateException: Cannot open session, you need to establish a connection first


I read the PRTG documentation, and they do have a RESTfulAPI that accepts HTTP requests, however it does not appear to be in the format that VMTurbo is requesting, the documentation states that the URL is the following:




The SSH connection is also confusing because that appears to be part of NetFlow and NFDUMP as the third error message would seem to indicate but this is definitely an sFlow target as you can see in the image attached.


Now this is where I really get confused. I read the VMTurbo documentation on configuring an sFlow target and I'm not really certain what to make of it as it seems contradictory:


Page two of the guide states the following:


NetFlow/sFlow: NFDUMP — VMTurbo provides an OVA download with NFDUMP preconfigured for NetFlow and

sFlow collection


However in the sFlow section it makes no mention of NFDUMP. Is this actually a requirement?




Network Control Module license

An SFlow data collector

You must have an SFlow data collector running on your network. Make sure the sflow-rt service is running. Operations Manager connects to the data collector through its REST API on port 8008. Credentials are not typically required to access the SFlow API. If you require a secure connection, contact VMTurbo Technical Support for assistance.


Adding sFlow Targets to Operations Manager

To add a NetFlow target (??), select the Network > sFlow option on the Target Configuration page and provide the following information:

Address: The IP address of the sFlow data collector

Username/Password: The credentials of an account Operations Manager can use to connect to the data collector.


Are parts of this documentation incorrect? I can see based off this why it's trying to connect on port 8008, but if credentials are not required to access the API why are they required fields in the target configuration? I would assume they are for the SSH connection but it's not clear.  Also, what sflow-rt service?


The only thing I can find online about sflow-rt are on these websites: - open source implementation, collects data from sFlow agents - download redirects to the previous link


Has anyone been able to get VMTurbo to successfully connect to an sFlow collector and if so which one? Or is there a recommended collector to use? Any help is appreciated, I've been banging my head against the wall trying to get this to work since yesterday afternoon.