在我从Vagrantfile中删除这一行后，我也遇到了同样的问题:

config.vm.network "private_network", type: "dhcp"

我把这行放回去后，VM加载正常。

我也有同样的问题。我认为问题可能是SSH密钥(错误的文件定位或其他东西，但我检查了很多次)，但你可能总是在配置部分添加用户名和密码(不使用SSH密钥)和运行gui，所以Vagrantfile中的代码应该看起来或多或少如下:

Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|

  config.ssh.username = "vagrant"
  config.ssh.password = "vagrant"

   config.vm.provider "virtualbox" do |vb|
     vb.gui = true
   end
end

In my case even if GUI was displayed I got black screen (no errors or possibility to login or anything else) and in console I got the Error: Connection timeout. Retrying... many times. I made sure I had VT-x (virtualization) enabled in BIOS, I checked many combinations of versions of both Virtual Box and Vagrant together and many Vagrant boxes (for some of them I didn't have black screen in GUI but still have connection problems). Finally I've updated VirtualBox and Vagrant again to the last versions and the problem still occurred.

最关键的是在运行vagrantup(使用Vagrantfile中的GUI)后，在VirtualBox中查看图标，如下图所示

虽然我在VirtualPC中没有错误(没有VT-x未启用的警告)，但我的V图标是灰色的，所以这意味着VT-x被禁用。正如我说的，我一直在我的BIOS中启用它。

Finally I realized the problem might by HYPER-V which I also installed and enabled to test sites on older Internet Explorer. I went to Windows Control Panel -> Programs and functions / Software and choose from the menu on left Turn on or Turn off Windows functions (hope you will find those, I use Polish Windows so don't know exact English names). I turned off Hyper-V, restarted PC and after running Virtual Box and vagrant up I finally had no errors, in GUI I have login screen and my V icon stopped to be gray.

我浪费了很多时间来解决这个问题(和许多电脑重启)，所以我希望这可能对任何在Windows上有问题的人有帮助-确保你在控制面板中关闭了Hyper-V。

删除文件:

C:\Users\UserName\\.vagrant.d\insecure_private_key

然后运行:

vagrant up

我通过在/etc/fstab中添加一个新条目来测试我的vagrant VM中挂载的文件夹。后来我注销了，跑了个流浪汉，但当我跑了个流浪汉，我得到:

SSH auth method: private key
Warning: Remote connection disconnect. Retrying...

I read all these posts and tried all the ones that seemed relevant for my case (except for vagrant destroy, which would have certainly fixed my problem, but was a last resort in my case). The post by @Kiee gave me the idea to try to boot my VM directly from the VirtualBox GUI. During the boot process the VM halted itself and was asking me if I wanted to skip mounting the test folder that I had added earlier to /etc/fstab. (That's why vagrant couldn't boot the VM.) After answering 'NO' the VM booted no problem. I logged in, removed the naughty line from my fstab, and shutdown the VM.

在那之后，流浪汉就能很好地踢足球了。

外卖吗?如果突然间vagrant无法引导回您的VM，请尝试直接从提供商引导(在我的情况下是VirtualBox)。您的引导可能挂起了与SSH完全无关的东西。

我在一台Windows 8.1的机器上遇到了同样的问题。连接超时和启用gui根本没有用，屏幕是黑色的。在我的情况下，修复是禁用“超V”

引用自Vagrant文档https://docs.vagrantup.com/v2/hyperv/index.html

警告:启用Hyper-V将导致VirtualBox、VMware和任何其他虚拟化技术不再工作。请参阅这篇博客文章https://www.hanselman.com/blog/SwitchEasilyBetweenVirtualBoxAndHyperVWithABCDEditBootEntryInWindows81.aspx，如果有需要其他管理程序的时候，可以简单地创建一个引导条目来启动没有启用Hyper-V的Windows。

在Homestead.yaml上寻找这条线:

config.vm.network "forwarded_port", guest: 80, host: 8080

并更改为:

config.vm.network "forwarded_port", guest: 80, host: 8000

然后在Homestead目录下运行:

vagrant destroy
vagrant up

看看它是否有效。