我已将运行 VistualBox 的 Vagrant (1.2.2) VM 设置为:private_network并在其上启动了 Sinatra 服务器。但是我无法连接到那个 Sinatra 实例。但是，VM 运行并响应 ping。
这是我的流浪文件
Vagrant.configure("2") do |config|
config.vm.box = "precise64"
config.vm.network :private_network, ip: "192.168.33.10"
end
所以我启动 Vagrant VM 并 ssh 进入它
prodserv$ vagrant up
Bringing machine 'default' up with 'virtualbox' provider...
[default] Setting the name of the VM...
[default] Clearing any previously set forwarded ports...
[default] Creating shared folders metadata...
[default] Clearing any previously set network interfaces...
[default] Preparing network interfaces based on configuration...
[default] Forwarding ports...
[default] -- 22 => 2222 (adapter 1)
[default] Booting VM...
[default] Waiting for VM to boot. This can take a few minutes.
[default] VM booted and ready for use!
[default] Configuring and enabling network interfaces...
[default] Mounting shared folders...
[default] -- /vagrant
prodserv$ vagrant ssh
Welcome to Ubuntu 12.04.2 LTS (GNU/Linux 3.2.0-23-generic x86_64)
* Documentation: https://help.ubuntu.com/
Welcome to your Vagrant-built virtual machine.
Last login: Thu May 23 14:01:05 2013 from 10.0.2.2
所以到这里为止一切都很好，花花公子。对 VM 的 ping 可以正常工作（我还检查了这确实是 VM 的 ip。所以在没有 vagrant up 的情况下进行 ping 会导致包丢失）
prodserv$ ping 192.168.33.10
PING 192.168.33.10 (192.168.33.10): 56 data bytes
64 bytes from 192.168.33.10: icmp_seq=0 ttl=64 time=0.543 ms
64 bytes from 192.168.33.10: icmp_seq=1 ttl=64 time=0.328 ms
伟大的！现在我在虚拟机上启动服务器
vagrant@precise64:~$ sudo ruby /vagrant/server.rb
== Sinatra/1.4.2 has taken the stage on 4567 for development with backup from Thin
>> Thin web server (v1.5.1 codename Straight Razor)
>> Maximum connections set to 1024
>> Listening on localhost:4567, CTRL+C to stop
这是对应的server.rb
require 'rubygems'
require 'sinatra'
get '/' do
puts "WOW!"
'Hello, world!'
end
如果我现在从来宾 VM卷曲到 Sinatra，一切正常，并且“你好，世界！” 将被退回。
vagrant@precise64:~$ curl 'http://localhost:4567'
Hello, world!vagrant@precise64:~$
#and the Sintra/Ruby process gets me this
WOW!
127.0.0.1 - - [23/May/2013 16:06:36] "GET / HTTP/1.1" 200 13 0.0026
但是，如果我尝试从主机卷曲，则连接被拒绝。
prodserv$ curl -v 'http://192.168.33.10:4567'
* About to connect() to 192.168.33.10 port 4567 (#0)
* Trying 192.168.33.10...
* Connection refused
* couldn't connect to host
* Closing connection #0
curl: (7) couldn't connect to host
那么这是什么一回事？