One possible solution was to use Windows (say XP) 32bit in a virtual machine. Obviously this is not the best solution, because starting a virtual machine just for a VPN is just too much sometimes!

The best solution was to find an alternative to Cisco VPN Client to work on my OS. This alternative is “Shrew Soft VPNClient” – a nice free tool that can be downloaded from the Shrew Soft site. Then, to configure it, I had to dig a bit on the net, until I found this great tutorial. I will summarize the steps for making the client to work (version 2.1.5):

1. Install the application (obvious)

2. Create a new site configuration (the button “Add”).

3. In the “General” tab enter your host name or IP (IPSec gateway)

4. In the “Client” tab, set “NAT Traversal” to “force-rfc”. Everything else remains the same.

5. In the “Name Resolution” tab check all the checkboxes.

6. In the “Authentication” tab set “Authentication Method” to “Mutual PSK + XAuth”. Then:

• in the “Local Identity” tab set “Identification Type” to “Key Identifier”, and then enter your group name in the “Key ID String” field (IPSec ID)
• in the “Remote Identity” tab set “Identification Type” to “Any”
• in the “Credentials” tab enter your group password in the “Pre Shared Key” field (IPSec secret)

7. “Phase 1″, “Phase 2″ and “Policy” should not be modified, if not instructed otherwise.

Save your settings, and then double-click your newly created connection. You will be prompted to enter the username and password for the XAuth authentication. After doing so, the connection will be created!

The image bellow should be of a bit of use:

After succeeding to configure this new client, I noticed that the connection goes on immediately; the client can be configured to minimize in the tray; the application is lightweight and fast. I would say that this client is a better alternative to Cisco VPN Client. Well done!