We have recently bought an ASA 5505, and I'm currently in the process of configuring it to support Windows L2TP VPN client connections. Unfortunately I just don't seem to be able to get this working. A big part of the problem is that ASA configuratino is completely new to me. I've used the following Cisco documents to try and set this up:
<a href="http://www.cisco.com/en/US/products/ps6121/products_configuration_guide_chapter09186a00806a81bc.html">Configuring L2TP over IPSEC (Command line)</a>
<a href="http://www.cisco.com/en/US/products/ps6121/products_configuration_guide_chapter09186a00806a81bc.html">Configuring L2TP over IPSEC (ADSM)</a>
<a href="http://www.cisco.com/en/US/products/hw/vpndevc/ps2030/products_configuration_example09186a00807213a7.shtml">L2TP Over IPsec Between Windows 2000/XP PC and PIX/ASA 7.2</a>
However, I recieve the following when trying to connect:
Error 789: The L2TP connection attempt failed because the security layer encountered a pprocessing error during initial negotiations with the computer.
I have attempted debugging on the ASA, however I can't seem to get it to log the UDP 1701 or L2TP session data. If I create a outside dynamic IPSEC rule, the error changes to 'network busy'. This seems to suggest the client is successfully hitting the firewall and begining negotions.. A show run displays the attached config:
I'd be really happy to hear from anybody who has experiance of succesfully configuring an ASA 5505 for use with L2TP, or anybody who has suggestinos on a way forward (and possibly a little help).