When used with "public_network" default gateway is missing on boot.

[GR360RY]

Example Vagrantfile:

Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
  config.vm.box = "boxcutter/ubuntu1404-desktop"
  config.vm.network "public_network"
end

Routing table with route -n after vagrant up:

vagrant@vagrant:~$ route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.0.2.0        0.0.0.0         255.255.255.0   U     0      0        0 eth0
10.100.200.0    0.0.0.0         255.255.255.0   U     0      0        0 eth1
169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 eth0

The box is missing 0.0.0.0 destination.
vagrant reload or reboot fixes this issue. If provisioning is required, default gateway should be fixed with explicit provisioning script. Here is my workaround:

$ grep vagrant_fix_default_gw.sh Vagrantfile
config.vm.provision :shell, path: "scripts/vagrant_fix_default_gw.sh"

Script contents:

$ cat scripts/vagrant_fix_default_gw.sh
route del default || true
route -n | grep -qe '^0.0.0.0' || sudo route add default gw `grep routers /var/lib/dhcp/dhclient.eth1.leases | sort -u | awk '{print $3}' | awk -F";" '{print $1}'`

This behaviour exists only with boxcutter/ubuntu1404-desktop. ubuntu/trusty64 box works as expected. Probably related to NetworkManager.

It would be nice to fix it in box itself.