So I got private networking. MY server was already made and in use and I decided to enable private networking on my servers. They do not communicate together.

I followed the guides, adding this to /etc/network/interfaces
auto eth1
iface eth1 inet static
address 10.137.80.219 Other servers ip 10.137.136.57
netmask 255.255.0.0

Did extensive testing between my servers. But had no luck at all, they don't ping via the private ips, only public ips, and that are infact in the same datacenter

Now things are just getting worse.

As now the interface isn't showing up, if I forcefully start it with ifconfig, no network information shows up. Basically It's worse than before following guides.

I have waited for 48 hours for Digital ocean to respond after they told me what to try and they still have not responded...very very poor customer support. Does the community have any answers?

PS. It's all on Ubuntu 16.04-17.04