How to switch between Lion 64-bit and 32-bit

前段时间在lion上装cisco vpn，启动时老是提示：

 

Error 51: Unable to communicate with the VPN subsystem.

Please make sure that you have at least one network interface that is currently active and has an IP address and start this application again.

 

花了一些时间查询与试验，真实原因是lion默认是64bit的， cisco vpn需要载入一些内核扩展，不是64位兼容的。

 

在这做个纪录，以备后用。 

 

怎样在32位与64位切换呢？ （来源自：http://itsmetommy.com/2011/09/20/cisco-vpnclient-error-51/）

 

To check which mode you are currently in, run this command on the terminal:

$ systemsetup -getkernelbootarchitecturesetting

To set your machine to boot into 64-bit mode, enter this command and reboot:

$ sudo systemsetup -setkernelbootarchitecture x86_64

To set your machine to boot into 32-bit mode, enter this command and reboot:

$ sudo systemsetup -setkernelbootarchitecture i386

To set your machine to boot into default mode, enter this command and reboot:

$ sudo systemsetup -setkernelbootarchitecture default

You settings are updated in /Library/Preferences/SystemConfiguration/com.apple.Boot.plist