It would be useful to select which network port a streaming output uses. This would allow a backup stream to be routed–via a different NIC–through an alternative network (e.g. 4G hotspot), thus protecting against network failure.
As it stands there is little point in sending a backup stream (from a single computer) as if the network fails then both streams will fail.
Thanks for using mimoLive and posting your feature request here.
This is something that needs to be set up in your network configuration. If you set up the routing table of that Mac correctly, it should already work as it is not mimoLive that decides what NIC to use.
Maybe I haven’t been clear. I would want to send the primary stream via one NIC and the backup stream via a different NIC.
Another way to do this would be to use a second computer with a different internet link but the same local subnet. You could send the video/audio via NDI to the second computer and stream from there to your backup destination. I wonder how to set up the streaming end though, I don’t know that YouTube or Facebook can take stream ingest for the same page/video from two origins. What streaming service would you use?
Yes, it is certainly possible to do this with a second computer. However, if the only thing you are doing is adding some network resilience, then a second computer is a bit overkill 
Of course, I don’t know if this would be a hard or easy thing to add, in terms of OS APIs, but it would be a really beneficial feature.
YouTube can absolutely take a backup ingest for the same stream. That is what their primary and backup servers are for! Different url, same stream key. I don’t know about Facebook or other services, but this is 100% possible on YouTube.
I wasn’t aware that this is the purpose of the backup ingest server. Interesting. I always assumed the backup server was for when the primary server isn’t available. Thanks for bringing this to my attention.
I still think this is already possible if you set the route to the primary server through NIC1 and the route to secondary server through NIC2. I found a discussion of this in this thread, although I haven’t tried that: https://superuser.com/questions/756134/how-to-direct-ip-route-through-specific-interface-in-os-x
Then, set up two live streaming destinations and turn them both on.
An interesting link. I wasn’t aware it was possible to setup routes like this (although not surprising given the unix underpinnings) and could be a useful workaround.
However, It doesn’t seem like a rather fragile fix, especially as it seems that macOS will rename interfaces over time. So I still think an option in the output Ui would be better, and easier to keep track of what’s going on.