Multicast

[StevenHunter]

I am running the LabVIEW 2019 Multicast example on two computers. The Sender is on an NI Industrial Controller running RT Linux. The receiver is on a Win10 PC. The sender is sending out the packets as confirmed with Singlewire Multicast Testing Tool on a third PC. Note that when I ran this tool, a dialog box popped up asking for permission to access the network software. All three computers plugged into a preconfigured switch.

The example Receiver VI on the Win10 PC sees no packets. Both example programs are unmodified other than to make the Sender deploy to the RT IC.

[550nm]

Hi Steven,

Are you running an EXE on the Windows PC?

A couple of things to try:

On the Windows PC, open Windows Firewall (even if it's not running).

Open "Allow a program or feature...".

Find your application and enable "Private" networks.

If you don't see your app/EXE, add it, allowing "Private" networks.

I don't think you want to allow "Public" networks.

If there's any security software running on the Windows PC the multicast packets my be getting blocked. Every firewall I've worked with is capable of logging dropped packets, but you might have to dig through the UI to find the path to the log file (assuming logging is enabled). See Windows Firewall\Advanced\Monitoring.

Hope it helps!

[StevenHunter]

I am just running the VI from LabVIEW on the Win10 PC.

My Windows Firewall says that it is managed by Symantic. I will have to get IT involved to translate.

[550nm]

FYI, apparently it's not uncommon for companies to block multicast packets.

(Weeks ago) I was unsuccessful sending a (multicast) "magic" packet to a machine, and concluded it was being blocked by company routers.

[StevenHunter · Accepted solution]

I have decided to give up on Multicast. It is too much of a hassle to get around existing firewall issues and I cannot risk corporate cyber security rules changing and breaking my system.