How can I make the Cisco VPN Client work with Lion? Worked in Snow Leopard and now gives error 51 and the sudo restart system command in Terminal i used to use doesn't work.  Any idea?
Have you tried using the on-board Cisco VPN Client? I had serious issues with Cisco's client (it kept kernel panik-ing my Mac) and had the IT department help me set up the built in client.

It basically works the same way as it does on an iPhone or iPad, so if you can connect with that device, you should be able to do so as well with your Mac.

What I needed:


the ip address of the VPN Server
the Group Name
the shared Secret


Login was done by using Active Directory authentication.

This is how I set it up:

In System Preferences -> Network hit the + button on the bottom of the list. The following dialog will open up



As you can see you'll need to choose VPN for the Interface and Cisco IPSec for the VPN Type. Name it as you please.

You'll find your newly created entry in the list, select it and you'll get a similar picture



Enter the IP Address you got from your IT department. You can leave the login stuff empty as you'll be prompted when connecting.

Hit the Authentication Settings... button.



Enter the group name (IT) and the shared secret. If your IT guys don't want to hand the data out to you, then ask them to kindly enter it for you. 

Hit OK and then Apply your settings and you should be pretty much able to connect now. I like to have the Show VPN status in menu bar option enabled in order to have quick access to turn on and off the connection. 

I also had to add one additional thing in order to be able to access remote computers just by their name instead of having to type name.domain. To do so I hit the Advanced... button and added our domain name to the Search Domains.



Hope it helps.