This article applies to all SSL products that use ipMIDI, not just Nucleus.
Many Mac Pro computers have dual Ethernet adapters, and if you count the Wi-Fi adapter, they have three adapters.
This can present a problem in certain network schemes for SSL ipMIDI controllers, because the ipMIDI multicast data (DAW control, MIDI Time Code, and MIDI Machine Control) will by default only go out the primary adapter.
The best solution is to connect every device to a common switch or router and not use the computer's secondary adapter for SSL, use it for something else.
If you must keep the dual interfaces with the SSL on the secondary, you can make it work by altering the routing table for the ipMIDI multicast address.
Essentially this forces multicast out of the interface you want (the secondary, SSL one).
This terminal command worked to change the routing table in High Sierra and likely works with later macOS versions:
sudo networksetup -setadditionalroutes <SSL-connected adapter name> 22.214.171.124 255.255.0.0 127.0.0.1
route add -p 126.96.36.199 mask 255.255.255.255 <SSL-connected adapter IP address>
- Apple has periodically changed their method for persistent routing table changes, so there is no guarantee they will not change it again in an update, which would mean you would have to find the new way Apple does this and re-implement.
- If you get a new Mac or flat install, you will also lose this route and have to redo.
- This would affect any app that uses 255.0.0.37; chances of that are very small, but perhaps not zero.
- Please note that when Wi-Fi is on, it automatically becomes the primary adapter. This is why Wi-Fi should be disabled when using SSL controllers.
- SSL ipMIDI DAW control uses multicast packets.
- Those multicast packets are going out of the macOS primary adapter, which is usually your internet. That's just how macOS does it, it doesn't know where to route them, it's all the same to the Mac.
- So they never get to the SSL.
- When you remove the internet connection, the SSL-attached adapter becomes the primary and it starts working.
- So if you can the best thing to do is not split the interfaces in this way. Put everything together on the same subnet. In 99% of cases, that is ok to do.
Please also see these related articles: