LabVIEW blocks UDP port 6000

[pawel]

Hi

I have noticed that when LabVIEW (8.6 but before as well) application which uses VISA is installed (by building the installer) the UDP port 6000 is blocked and no other program can use it.

Does anyone know how to check which other ports are blocked by VISA?

thanks

Pawel

[smercurio_fc]

UDP ports above 6000 are used by the network shared variable server. They also use UDP port 2343.

[pawel]

Hi

Can I disable the network shared variable server? How?

thanks

Pawel

[smercurio_fc]

It's a service called "National Instruments Variable Engine" that you start/stop via the operating system. On Windows this is done with the Services control panel. If you want to do it programmatically see here: How do I Programmatically Start and Stop the Shared Variable Engine?

Message Edited by smercurio_fc on 04-29-2009 04:48 PM

[pawel]

Hi

I just checked that the NI Variable Engine is not part of my installation, so how come it can block the USP ports 6000 and other?

Did I miss something?

thanks

Pawel

[smercurio_fc]

How did you check? Did you actually look at the "Services" MMC plug-in (Administrative Tools -> Services) and see the service not there or did you do Add/Remove Program and see what's listed in the "National Instrument Software" component? If you did the latter, it won't show up, as it's a sub-component.

[pawel]

I checked the services, it is not there.

[smercurio_fc]

Odd. Let's try this a different way. Open up a command prompt and type

netstat -a -o

You should get a great big list of all the open ports. The last column will show you the process ID that has that port opened. You can find out the name of the process by opening Task Manager, switching to the "Processes" tab, then select the View -> Select Columns... menu item and check the "PID (Process Identifier)" box. This should allow you to identify which process has that specific port open.

What do you get?

[pawel]

Hi

Good idea.

Here is what I have:

Before VISA installation

C:\Documents and Settings\Administrator>netstat -a -p UDP

Active Connections

  Proto  Local Address          Foreign Address        State
  UDP    PDS2k:microsoft-ds     *:*
  UDP    PDS2k:netbios-ns       *:*
  UDP    PDS2k:netbios-dgm      *:*
  UDP    PDS2k:isakmp           *:*
  UDP    PDS2k:4500             *:*

C:\Documents and Settings\Administrator>netstat -a -p UDP

After VISA installation

Active Connections

  Proto  Local Address          Foreign Address        State
  UDP    PDS2k:microsoft-ds     *:*
  UDP    PDS2k:1027             *:*
  UDP    PDS2k:2343             *:*
  UDP    PDS2k:5000             *:*
  UDP    PDS2k:5001             *:*
  UDP    PDS2k:5002             *:*
  UDP    PDS2k:6000             *:*
  UDP    PDS2k:6001             *:*
  UDP    PDS2k:6002             *:*
  UDP    PDS2k:netbios-ns       *:*
  UDP    PDS2k:netbios-dgm      *:*
  UDP    PDS2k:isakmp           *:*
  UDP    PDS2k:4500             *:*
  UDP    PDS2k:5353             *:*

As I can see just the instalation of the VISA 4.4 blocks the port 6000.

Is there a way I can control it somehow and  remove the port blocking?

thanks

Pawel

[smercurio_fc]

The intent of the -o was to get the process ID so you could identify which process had the port open, which was the whole point. I ran the command on a system here and found that UDP port 6000 was being used by the Lookout Citadel Server.