即在运行vagrant up时得到其的下载路径，如：
https://vagrantcloud.com/ubuntu/boxes/xenial64/versions/20190101.0.0/providers/virtualbox.box
然后直接在浏览器上访问该网址来下载该box
先查看本地安装的box：
userdeMBP:ubuntu-16.04 user$ vagrant box listhashicorp/precise64 (virtualbox, 1.1.0)hashicorp/vagrant-share (virtualbox, 0.1.0)tknerr/baseimage-ubuntu-12.04 (docker, 1.0.0)
再将得到的box文件手动添加进去：
userdeMBP:ubuntu-16.04 user$ vagrant box add --name ubuntu/xenial64 /Users/user/ubuntu-16.04/xenial-server-cloudimg-amd64-vagrant.box==> box: Box file was not detected as metadata. Adding it directly...==> box: Adding box 'ubuntu/xenial64' (v0) for provider: box: Unpacking necessary files from: file:///Users/user/ubuntu-16.04/xenial-server-cloudimg-amd64-vagrant.box==> box: Successfully added box 'ubuntu/xenial64' (v0) for 'virtualbox'!
然后再查看本地果然多了一个新的box：
userdeMBP:ubuntu-16.04 user$ vagrant box listhashicorp/precise64 (virtualbox, 1.1.0)hashicorp/vagrant-share (virtualbox, 0.1.0)tknerr/baseimage-ubuntu-12.04 (docker, 1.0.0)ubuntu/xenial64 (virtualbox, 0)
然后再在相应vagrantfile对应的目录下运行vagrant up即可运行起来了：
userdeMBP:ubuntu-16.04 user$ vagrant upBringing machine 'default' up with 'virtualbox' provider...==> default: Importing base box 'ubuntu/xenial64'...==> default: Matching MAC address for NAT networking...==> default: Setting the name of the VM: ubuntu-1604_default_1546496409973_90048==> default: Vagrant has detected a configuration issue which exposes a==> default: vulnerability with the installed version of VirtualBox. The==> default: current guest is configured to use an E1000 NIC type for a==> default: network adapter which is vulnerable in this version of VirtualBox.==> default: Ensure the guest is trusted to use this configuration or update==> default: the NIC type using one of the methods below:==> default: ==> default: https://www.vagrantup.com/docs/virtualbox/configuration.html#default-nic-type==> default: https://www.vagrantup.com/docs/virtualbox/networking.html#virtualbox-nic-type==> default: Clearing any previously set network interfaces...==> default: Preparing network interfaces based on configuration... default: Adapter 1: nat==> default: Forwarding ports... default: 22 (guest) => 2222 (host) (adapter 1)==> default: Running 'pre-boot' VM customizations...==> default: Booting VM...==> default: Waiting for machine to boot. This may take a few minutes... default: SSH address: 127.0.0.1:2222 default: SSH username: vagrant default: SSH auth method: private key default: Warning: Connection reset. Retrying... default: Warning: Remote connection disconnect. Retrying... default: default: Vagrant insecure key detected. Vagrant will automatically replace default: this with a newly generated keypair for better security. default: default: Inserting generated public key within guest... default: Removing insecure key from the guest if it's present... default: Key inserted! Disconnecting and reconnecting using new SSH key...==> default: Machine booted and ready!==> default: Checking for guest additions in VM... default: The guest additions on this VM do not match the installed version of default: VirtualBox! In most cases this is fine, but in rare cases it can default: prevent things such as shared folders from working properly. If you see default: shared folder errors, please make sure the guest additions within the default: virtual machine match the version of VirtualBox you have installed on default: your host and reload your VM. default: default: Guest Additions Version: 5.1.38 default: VirtualBox Version: 5.2==> default: Mounting shared folders... default: /vagrant => /Users/user/ubuntu-16.04
然后使用vagrant ssh即可进入：
userdeMBP:ubuntu-16.04 user$ vagrant sshWelcome to Ubuntu 16.04.5 LTS (GNU/Linux 4.4.0-141-generic x86_64) * Documentation: https://help.ubuntu.com * Management: https://landscape.canonical.com * Support: https://ubuntu.com/advantage Get cloud support with Ubuntu Advantage Cloud Guest: http://www.ubuntu.com/business/services/cloud0 packages can be updated.0 updates are security updates.New release '18.04.1 LTS' available.Run 'do-release-upgrade' to upgrade to it.vagrant@ubuntu-xenial:~$