主机成功引导后，Vagrant ssh挂起

下面是我的Vagrant文件，在启动此主机时，它在

  ==> sawtoothclient: Waiting for machine to boot. This may take a few minutes...
      sawtoothclient: SSH address: 127.0.0.1:2222
      sawtoothclient: SSH username: vagrant
      sawtoothclient: SSH auth method: private key

流浪者重新加载没有帮助，我不想每次登录到虚拟主机时流浪者停止

VAGRANTFILE_API_VERSION = "2"
Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
    config.vm.define "sawtoothclient", primary: true do |sawtoothclient|

        sawtoothclient.vm.box = "ubuntu/xenial64"
        sawtoothclient.vm.hostname ="sawtoothclient"
        sawtoothclient.vm.network :public_network
        #fubuntuone.vm.provision :shell, :privileged => false, :path => "bootstrap_ubuntu.sh"
        sawtoothclient.vm.synced_folder "/home/feynman/Programs/SawtoothClient/", "/home/vagrant/SawtoothClient/"
        sawtoothclient.vm.provider :virtualbox do |vb|
           vb.gui = false
           vb.memory = 2048
           #vb.customize ["modifyvm", :id, "--natdnshostresolver1", "on"]
           #vb.customize ["modifyvm", :id, "--natdnsproxy1", "on"]
        end

    end
end

我的UFW防火墙规则是

  To                         Action      From
  --                         ------      ----
  Anywhere                   ALLOW       192.168.1.0/24 

但是当我加上

 sudo ufw allow 22

vagrant ssh成功了，据我所知，我无法理解为什么vagrant必须使用主机IP将ssh连接到vagrant主机，这已包含在最初添加到ufw防火墙的防火墙规则中

 Vagrant 2.1.4

 vboxmanage -v
 output: 5.2.18r124319