Port Conflicts with NI Software

Updated Jul 3, 2018

Reported In


  • LabVIEW

Operating System

  • Windows

Issue Details

How to solve when my program is having a port conflict with a National Instruments program or service running? 


National Instruments published a Configuring Software and Hardware Firewalls to Support National Instruments Products with a list of all external ports used by our software in order to help users configure their firewalls properly. If you have not already, check there first and find if you are trying to use a statically defined port that an NI service is reserving. If you are, the best course of action is typically to change your port. 

In addition to those statically defined ports, we use some ephemeral or dynamic ports for loopback communication between services. These ports are allocated on service start and are pulled from the Windows dynamic port range. If your program is using a statically defined port within the Windows dynamic port range you will run into intermittent port conflicts. Changing your program to use a port outside of the dynamic range is typically best. More information on the dynamic port range can be found in this The default dynamic port range for TCP/IP has changed since Windows Vista and in Windows Server 2008.