If you use Vagrant & VirtualBox often, its important to to keep your Guest Additions up-to-date. Occasionally you’ll run into weird network or shared folers bugs, and it is important to rule out the guest additions as the problem. The most simple way it to use the vagrant plugin vagrant-vbguest. If you’re on Vagrant 1.1 or higher, you can simple use the follow command:
[bash]
vagrant plugin install vagrant-vbguest
[/bash]
Justin Carmony 