这里有很多很好的答案，我不能全部读完，但是，我只是来给我的一点贡献。我有两个不同的问题:

vagrant up wasn't able to find my ssh 'id_rsa' (because I didn't have it yet, at that time): I ran ssh-keygen -t rsa -b 4096 -C "myemailaddress@mydomain.com", based on this GitHub's article, and voilá, steped through that; Then, I got the same problem of this question "Warning: Connection timed out. Retrying...", eternally...: So, after reading a lot, I've restarted my system and looked at my BIOS (F2 to get there, on PC), and there were Virtualization disabled. I've enabled that, saved, and started the system once again, to check if it has changed anything.

从那以后，流浪起来就像有魔力一样!现在是凌晨4点，但它还在跑!多酷啊，hã?我知道很少有像我这样的受虐狂开发者会在Windows上尝试这个，特别是在Windows 10上，我只是无法不忘记来这里并留下我的话…另一个重要的信息，是，我试图设置Laravel 5，使用Homestead, VirtualBox，作曲家等。这是有效的。所以，希望这个答案能对你有所帮助，就像这个问题和答案对我有所帮助一样。祝福你。G-bye !

My solution turned out to be none of the above exactly. I'm running Ubuntu 14 as guest inside a Windows 7 host. I had been running this vagrant box fine, but I started it up again after not using it for a couple of months, and it kept coming up with the SSH connection timeout. It turned out that somehow the key pair didn't work - so I copied the Vagrant public key into Ubuntu according to the instructions on this page. But that wasn't all. I then discovered that the private key in my base box was different than the private key here. Putting this private key in as the vagrant_private_key file in C:\Users\your-user.vagrant.d\boxes\vagrant-box-name\nnnnnnnn\virtualbox after placing the public key into Ubuntu fixed the problem.

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。

我也遇到过同样的问题，但是上面提到的解决方案都不适合我! 我通过将Vagrant降级到1.6.2来解决这个问题，现在它可以工作了!

我发现在MacOS上使用VirtualBox将此添加到Vagrantfile将让你更进一步:

config.vm.provider 'virtualbox' do |vb|
  vb.customize ['modifyvm', :id, '--cableconnected1', 'on']
end

我解决了这个问题，如果其他人有类似的问题，我会回答。

我所做的是:我启用了虚拟框的GUI，让它在启动时等待输入，以选择我是想直接引导到ubuntu还是safemode等等。

要打开GUI，你必须把这个放在你的Vagrantfile配置中:

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