MacだとbrewでVirtualBox?とともに入れるのがイイかな
http://www.vagrantbox.es/ からboxを探して
$ vagrant box add https://atlas.hashicorp.com/envimation/boxes/ubuntu-xenial ==> box: Loading metadata for box 'https://atlas.hashicorp.com/envimation/boxes/ubuntu-xenial' This box can work with multiple providers! The providers that it can work with are listed below. Please review the list and choose the provider you will be working with. 1) virtualbox 2) vmware_desktop Enter your choice: 1 ==> box: Adding box 'envimation/ubuntu-xenial' (v1.0.3-1498871542) for provider: virtualbox box: Downloading: https://app.vagrantup.com/envimation/boxes/ubuntu-xenial/versions/1.0.3-1498871542/providers/virtualbox.box ==> box: Successfully added box 'envimation/ubuntu-xenial' (v1.0.3-1498871542) for 'virtualbox'!
$
でダウンロード完了
$ vagrant box list envimation/ubuntu-xenial (virtualbox, 1.0.3-1498871542) $