macosxhints.com – OS X VPN client and Cisco ASA
Summary: This hint is for Network Engineers who want their firewalls to accept VPN connections from standard OS X L2TP / IPSec clients (should also work for Windows and Linux clients). If you are not a network engineer, but are having trouble connecting to one of these devices, you can also forward this tip to your company’s “firewall person,” so that they can fix it.
Problem: A Cisco ASA or PIX firewall can be a VPN server, but a basic VPN configuration will not allow the default OS X L2TP/IPSec client to connect, even though the Cisco client will. It may not be convenient to distribute the Cisco VPN clients, or your users may not wish to use them.