Dear, I use a platform with Juno Openstack and vlan neutron networking. For some reason I need to add static route to instances not passed by cloud-init. Cloud-init give the instance the default gw and this is ok,

 Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.6.1     0.0.0.0         UG    0      0        0 eth0
192.168.6.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0

but I need one other static route I don't want to be passed by cloud-init, so I added it manually in the instance itself:

route add -net 192.168.0.0 netmask 255.255.255.0 gw 192.168.6.254

obtaining what I want:

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.6.1     0.0.0.0         UG    0      0        0 eth0
192.168.6.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0
192.168.0.0     192.168.6.254   255.255.255.0   UG    0      0        0 eth0

The problem is that after some random time the static route

192.168.0.0     192.168.6.254   255.255.255.0   UG    0      0        0 eth0

disappear.

And this happen obviously without reboot ore recreating or restating network or something else. Maybe "cloud-init" do a refresh after a while to the instance? Thanks for your support,

Ivan