vagrant up启动时如果设置成private_network报如下错：
Bringing machine \'default\' up with \'virtualbox\' provider... [default] Importing base box \'precise64\'... [default] Matching MAC address for NAT networking... [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... There was an error while executing `VBoxManage`, a CLI used by Vagrant for controlling VirtualBox. The command and stderr is shown below. Command: ["hostonlyif", "create"] Stderr: 0%... Progress state: E_INVALIDARG VBoxManage.exe: error: Failed to create the host-only adapter VBoxManage.exe: error: Assertion failed: [!aGuid.isValid()] at \'D:\tinderbox\win-4.3\src\VBox\Main\src-server\HostNetworkInterfaceImpl.cpp\' (74) in long __cdecl HostNetworkInterface::init(class com::Bstr,class com::Bstr, class com::Guid,enum __MIDL___MIDL_itf_VirtualBox_0000_0000_0034). VBoxManage.exe: error: Please contact the product vendor! VBoxManage.exe: error: Details: code E_FAIL (0x80004005), component HostNetworkInterface, interface IHostNetworkInterface VBoxManage.exe: error: Context: "int __cdecl handleCreate(struct HandlerArg *,int,int *)" at line 66 of file VBoxManageHostonly.cpp
原因是virtualbox4.3.26版本有bug，无法创建host-only网卡
解决办法：下载4.3.24版本安装（安装会覆盖掉之前的版本，但不影响之前配置的虚拟机）
参考：http://www.tuicool.com/articles/q2YrMzn
https://github.com/puphpet/puphpet/issues/272
