Comment 7 for bug 1639754

@brian-murray, verified on xenial/kvm machine with configuration:

$ cat /etc/netplan/00-snapd-config.yaml
network:
  ethernets:
    eth0:
      dhcp4: true
  version: 2

With nplan 0.13~16.04:
$ ip route
default via 10.0.3.1 dev eth0
default via 10.0.3.1 dev eth0 proto dhcp src 10.0.3.223 metric 1024
10.0.3.0/24 dev eth0 proto kernel scope link src 10.0.3.223
10.0.3.1 dev eth0 proto dhcp scope link src 10.0.3.223 metric 1024

With nplan 0.14~16.04:
$ ip route
default via 10.0.3.1 dev eth0
default via 10.0.3.1 dev eth0 proto dhcp src 10.0.3.223 metric 100
10.0.3.0/24 dev eth0 proto kernel scope link src 10.0.3.223
10.0.3.1 dev eth0 proto dhcp scope link src 10.0.3.223 metric 100