My question is: How do I configure a multicast route in Ubuntu such that it will always be present even after a reboot, and will not be removed automatically by any networking daemons Ubuntu runs?
Here is some background of my situation and what I've tried. I am stuck with Ubuntu 16.04 LTS and cannot change that. I cannot install any updates as it may break undocumented dependencies in my fragile build system (don't ask). I can add new software which is not already present. I have multiple interfaces on my Linux server and I need to have a permanent multicast route configured. I tried manually entering the route with:
Code:
user@hostname:~$ sudo ip route add 239.192.0.85/32 dev enp5s2
and everything worked excellently as confirmed by:
Code:
user@hostname:~$ route -n | grep 239
239.192.0.85 0.0.0.0 255.255.255.255 UH 0 0 0 enp5s2
BUT NO DICE!!! -- After some time passes my route disappears.
It seems like Ubuntu has some sort of networking daemon running in the background who's main job seems to be going around and undoing any of the work someone has done manually and deliberately unless they have done it THE ONE AND ONLY CORRECT WAY (whatever that is?).
I tried to install the route using Ubuntu's gui (unity-control-center network) and there was a spot for IPv4 and routes, however when I enter a multicast route it does not work as desired. The gui shows the configuration as a static IP address. Then once I save and close out the gui no multicast route or secondary IP is added anyway proving that the gui seems to be pretty worthless for anything beyond the most basic configuration.
I also tried adding a route to /etc/network/interfaces but it does not seem to have any effect when I restart the whole machine, or when I restart NetworkManager (which might not even be the right way to apply the settings).