Send multicast to a specific NIC

[Steve Gase]

Thought I'd pass this info along... 


I'm rebuilding my PC (upgraded to Win8.1) and that is causing me to reinstall software including xLights -- which talks to the EtherDongle.


As you may be aware, the EtD uses multicast E1.31.  When your PC sends multicast in large number of packets (20 per second, and maybe 32 512-channel universes) it could have a negative effect on your home network.  I have had some of my PCs slow to a crawl when xLights is sending multicast traffic. 


To solve this, I added a second NIC for my E1.31 traffic.  When xLights sends multicast packets, it MAY send it to the wrong NIC, but to tell your PC which NIC to use, you can create a "static route".


Here is my setup:


192.168.1.24 :: my PC's IP address on my home network
192.168.0.24 :: my PC's IP address on my E1.31 network  (this network is shared with the EtD !!)


Run this command on your PC one time: (the -p option makes it persistent -- or retained after a reboot)

Code: You are not allowed to view links. Register or Login

route -p add 239.255.0.0 mask 255.255.0.0 192.168.0.24 metric 1

Note the IP address "192.168.0.24" is specified -- this is the IP address for my NIC on the E1.31 network.
The network 239.255.0.0 and its associated mask is used to specify multicast traffic -- all multicast traffic will be sent over the second NIC.


(Thanks David for originally helping me with the syntax!)

[tbone321]

Also make sure that the second NIC is on a separate physical network and is NOT connected to the same one as the first primary NIC or this will not eliminate the problem.  Thanks for the routing command Steve, this will help many people that use the ETD and their PC to run the show.  IMHO, the best method would be to use either the Conductor or a pi with FPP to run the show since  XLights can easily convert most show sequence files to run on either device.

[Steve Gase]

IMHO, the best method would be to use either the Conductor or a pi with FPP to run the show since  XLights can easily convert most show sequence files to run on either device.

I definitely agree on the FPP...  however in my workshop I use the PC direct to EtD then hub. 


To avoid multicast I could insert the FPP (using unicast E.1.31) and have the FPP-to-hub with Pixelnet. 


There's so many ways to do this stuff...

[tbone321]

I definitely agree on the FPP...  however in my workshop I use the PC direct to EtD then hub. 

Which puts it on a separate physical network and makes the command that you shared work exactly as expected. 

To avoid multicast I could insert the FPP (using unicast E.1.31) and have the FPP-to-hub with Pixelnet. 

I was unaware that FPP could receive E1.31 and output PixelNet.

There's so many ways to do this stuff...

So true and the cause of so many issues as well.