Cisco VPN for Win7 x64

The Cisco VPN client won't run on 64bit versions of windows, and Cisco has no plans to ship a 64 bit client anytime soon.  In order to get VPN working on my shiny new Windows 7 x64 install, I tried to get the Cygwin/linux vpnc client working.  I ran into a number of problems, so this post explains how it can be done and hopefully will help you avoid the same problems I had.  I spent a lot of time researching information on the 'net, and wound up tweaking steps a bit and hacking scripts myself, but much of this is based on work by Li Zhao and Salty.

NOTE: update 22 Mar 2010 - The Shrew.net client supports Win7 now, and seems to work flawlessly. It’s a much better option if you don’t already have a need for Cygwin. 

To get Cisco VPN working on an x64 Windows 7, you need:

• Cygwin - a wonderful set of tools to emulate a linux environment on windows
• OpenVPN - to provide a virtual TAP network adapter
• VPNC - the VPN Client