atomic-openshift-node service fails to initialize

Issue

The atomic-openshift-node service fails to initialise correctly due to:
SDN node startup failed: Failed to start plugin: /usr/sbin/ip failed: '/usr/sbin/ip route add 172.17.0.0/16 dev tun0': exit status 2

For some reason docker0 exists in the route table, but not in the tun0 interface:

# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default          1.1.1.1        0.0.0.0         UG    0      0        0 eth0
1.1.1.2        0.0.0.0         255.255.255.224 U     0      0        0 eth0
link-local      0.0.0.0         255.255.0.0     U     1002   0        0 eth0
172.17.0.0      0.0.0.0         255.255.0.0     U     0      0        0 docker0