In case there are many people using your vagrant file - you might want to set name dynamically. Below is the example how to do it using username from your HOST machine as the name of the box and hostname:
require 'etc'
vagrant_name = "yourProjectName-" + Etc.getlogin
Vagrant.configure("2") do |config|
config.vm.box = "ubuntu/xenial64"
config.vm.hostname = vagrant_name
config.vm.provider "virtualbox" do |v|
v.name = vagrant_name
end
end