Start looking up the virtual machine by it's UUID in vSphere again. Looking up by IP address is problematic and can either not return a VM entirely, or could return the wrong VM.

Retrieves the VM's UUID in one of two methods - either by a `vm-uuid` entry in the cloud config file on the VM, or via sysfs. The sysfs route requires root access, but restores the previous functionality.

Multiple VMs in a vCenter cluster can share an IP address - for example, if you have multiple VM networks, but they're all isolated and use the same address range. Additionally, flannel network address ranges can overlap.

vSphere seems to have a limitation of reporting no more than 16 interfaces from a virtual machine, so it's possible that the IP address list on a VM is completely untrustworthy anyhow - it can either be empty (because the 16 interfaces it found were veth interfaces with no IP address), or it can report the flannel IP.