Ok, I have issue with Mac to get connect to Cisco VPN. I have two system with OSX 10.7.1 one of them is connection normally and the other didn't!!!
the second one it established the connection and the log file shows DNS and IP and everything and then disconnect with kernel utun0 error 6.
Thanks in advance!
FYI, If you use IP-sec over L2TP you can try to activate the protocol MS-CHAP-V2 on the RA profile, and use the normal l2tp over ipsec client on the mac (not the IPSec for cisco).
Hope this will help you.