Configuring a 2nd Network Card for your ECG multicast traffic


Full time elf
May 20, 2010
Irvine, the OC, CA
Heres some setup steps that worked for me when setting up my windows 7 system to use a seperate network card for the EthConGateway traffic.

Issue: Madrix sACN has limited setup to allow network traffic to be directed to an network interface, and only allows Multicast configuration. Due to the high network utilisation this caused a slowdown on my default network.

resolution: Create a Static route on your windows network routing table to send the multicast traffic to a 2nd Network card.

1. route print to get the interface

C:\Windows\system32>route print
Interface List
14...00 1e 2a b2 3f df ......Realtek RTL8169/8110 Family PCI Gigabit Ethernet NIC (NDIS 6.20)
11...00 21 85 36 ba 91 ......Realtek RTL8168C(P)/8111C(P) Family PCI-E Gigabit Ethernet NIC (NDIS 6.20)
1...........................Software Loopback Interface 1
12...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
13...00 00 00 00 00 00 00 e0 Teredo Tunneling Pseudo-Interface

I identified 14 as my 2nd Nic on

To create a route for the subnet (sACN Multicasts on 239.255.x.x)

subnet netmask gateway
route -p ADD MASK METRIC 1 IF 14

note -p for persistent to keep in routing table after reboot

I have my 2nd NIC connected to its own switch which also has the DR4 and DR8 plugged in to it.

So here are the results of my changes to my routing table

route print

IPv4 Route Table
Active Routes:
Network Destination Netmask Gateway Interface Metric 266 On-link 266 On-link 266 On-link 266 On-link 306 On-link 306 On-link 306 On-link 266 On-link 266 On-link 266 On-link 1 On-link 306 On-link 266 On-link 266


There are no rules, and those are the rules.
Community project designer
May 19, 2010
Knoxville TN USA
I had sent Neil a head's up based on linux routing knowledge and the hope that it would translate to the windows environment.

Only one addition I would add - YMMV, IMHO, Not Safe For Children Under ....

This solution could work great for you, but then it also could mess up some other software/hardware configuration you are using.

So proceed with caution but it should not cause any permanent harm.

It is also possible that refinements to this technique would work that would narrow the net starting address and netmask down to a block of 256 universes (or more or less) and then you could route block #1 to one interface and block #2 to another.

All of this is only needed if you are working with Madrix or MagicQ or some other software which does not allow control of multicast destinations. Our Vixen plugin and the LSP driver (which is a derivative) do not need this. They have interface control at the universe level.