National Instruments mDNS Responder Service

[Justin_E]

2and4,

The beta software is likely what's messing you up. In LV2010 beta, I believe the service may have been named "NISystemWebServer" instead of "niSvcLoc". Check the properties tab of the NI System Web Server... if the Service Name is anything other than "niSvcLoc" then that's the problem. You'll have to uninstall/reinstall all NI software to fix this.

[ASharma]

You're right: that service is named "NISystemWebServer".  So I have to uninstall and reinstall ALL NI software, huh?  Including all older versions of LabVIEW???

Well, I was looking for an excuse to buy a new laptop.  This may be it.  Thanks...

[wantacobra]

Two additional observations:

1.  National Instruments RIO Server is set to manual rather than automatic.

2.  NI Application Web Server is set to Automatic and has started.  NI Application Web Server(64 bit) is disabled.

I have two machines that exhibit the same problem.  Both are setup very similarly. 

Win 7, Dell Optiplex 780, LabView 2010 SP1, connected to company network and running associated security profiles. 

[Justin_E]

Hey Mike,

It sounds like a DNS misconfiguration. I see this message in Event Viewer:

Name resolution for the name pwrutc.com timed out after none of the configured DNS servers responded.

Is pwrutc.com correct? Should it be pwr.utc.com?

[wantacobra]

Justin

pwrutc.com is correct.

Do you create any debug log file writes during the startup of mDNS service so we can see what is hanging this service?

Mike

[wantacobra]

Justin

How does a proxy server fit into the startup of mDNS service?  Do you know where the service is hanging? Are you trying to locate a DNS server?

Mike

[wantacobra]

Justin

What is the timeout value for the response?  I am seeing 8 hops for a total of about 280ms.

Mike

[wantacobra]

Justin

I have our local IT guys looking at the problem.  They are wondering why there are quite a few DNS queries to the local machine. 

Can you elaborate in more detail what mDNS service is attempting to do?

Thanks

MIke

[JoshuaP]

mDNS is an industry standard for discovering network resources such as printers or file shares on your local network.  It leverages the same protocol as DNS, but uses port 5353 instead of the standard DNS port 53 to limit the traffic to just the local network.  NI leverages it for discovering DAQmx and GPIB network devices, Ethernet instruments like LXI, LabVIEW Real-Time targets, and resources like network shared variables.  If IT looks a bit closer they should notice that most of the DNS traffic should be on port 5353 not 53.

[Justin_E]

Hey Mike,

One possibility is the service is hanging by waiting on one of the namespace service providers on the system. We can test this with the C:\Program Files\National Instruments\Shared\mDNS Responder\nimdnsNSPTool.exe utility. 

1) Open an administrative command prompt, navigate to that directory, and enter 'nimdnsNSPTool.exe -help' to get familiar with the commands you'll be using

2) 'nimdnsNSPTool.exe -list' to view all NSPs on the system.

3) Try disabling one NSP at a time (using the -disable option) and restarting nimDNSResponder to see if it starts successfully.