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Home > Success Center > Netflow Traffic Analyzer (NTA) > NTA - Knowledgebase Articles > NetFlow Service is inaccessible. Verify that service is 'Started'

NetFlow Service is inaccessible. Verify that service is 'Started'

Created by Joseph Esquitin, last modified by Verwin Ubana on Sep 26, 2018

Views: 3,813 Votes: 4 Revisions: 13

Updated Sept 26, 2018


The following error is displayed when opening any of the NetFlow pages or NTA settings page:

NetFlow Service inaccessible. Verify that service is 'Started'


  • NTA 3.x
  • NTA 4.x



This issue may be caused by any of the following:

  • There is a licensing issue. For example, the NTA license doesn't match volume of NPM license.
  • The IP address or hostname of Orion server has been changed or migrated to another server keeping the old DB; Fix: Either contact support to solve this, or go to Orion Settings > Details > Polling Engines > check that you have two primary polling engines > delete the old one. Then go to NetFlow summary view > NetFlow services resource > Edit > Delete the old NetFlow service.
  • The Orion, Flow storage or  SQL server have a different time and time zone.
  • The service is stopped.
  • The service is missing on the primary server. 
  • There are duplicate flow engines in the database table called "Flowengines"
  • Upgraded the Flow Storage Database and never ran the install on the primary. 



Licensing issue

Obtain and apply the correct license to your product.


IP address issue
  1. Contact SolarWinds support or go to Orion Settings > Details > Polling Engines
  2. Check that you have two primary polling engines.
  3. Delete the old polling engine.
  4. Go to NetFlow summary view > NetFlow services resource > Edit and delete the old NetFlow service.
Time and time zone issue


Verify that Orion, SQL and Netflow Flow Storage servers are on the same time and time zone.


NTA Service is stopped:


1. Start NTA service. 

Open services Start -> Run -> services.msc


  1. Find The Solarwinds Netflow Service
  2. Right Click and Start the service


NTA Collector is missing:


1. Checked database manager 

2. Query the flow engines table if the entry is missing. 

3. Open control panel and run repair on NTA to correct the problem.


NTA Flow Storage Database version mismatch:


1. Install NTA on the primary server to fix the version mismatch. 


NTA 4.2.0 when a device is enabled for NBAR this error will be returned:


1. Install NTA 4.2.1 

2. NTA 4.2.1 addresses fixes for NBAR stability and overall application performance. 


Error on Additional web server after upgrading to 4.2.0


  1. Temporary work around:  Restart the Solarwinds services on the additional web server
  2. Fix:  Issue has been fixed in Netflow 4.2.1. Upgrade to this version as a permanent fix


Last modified