Comment 19 for bug 1561250

To confirm Toni's comment, my testing yields the same result:

$ vboxmanage --version
5.0.20r106931

$ vagrant --version
Vagrant 1.8.1

$ vagrant box list | grep xenial
ubuntu/xenial64 (virtualbox, 20160531.0.0)

$ vagrant init ubuntu/xenial64
$ vagrant up

$ vagrant ssh -- sudo grep hosts /etc/nsswitch.conf
sudo: unable to resolve host ubuntu-xenial
hosts: files dns