Alternative Cisco VPN clients for Windows XP
Solution 1:
Install a virtual server inside the remote network and use RRAS for VPN on it. Then expose the relevant ports through the ASA.
That way all XP/Vista clients can connect reliably.
Mike
Solution 2:
Have you taken a look at shrew?
http://www.shrew.net/software. I've used it on windows machines as a replacement for a specific version of the cisco client which was not playing nicely with windows 7.
vpnc combined with network-manager-vpnc is a great option if you're on a linux platform though.
Solution 3:
Cisco VPN is proprietary and will not work with anything but Cisco VPN :-) It is IPSec but it is not compatible with other IPSec clients.
Solution 4:
Came across this article on how to get Windows Vista to connect to a Cisco PIX using a native client. Since ASA is mostly just a glorified PIX, these options might also work for you.
I also have to agree with the previous posts that the 'vpnc' client that you can install on Linux is just great, as it does not force any network routes or blockage like the official Cisco client does. You decide what your computer routes through the tunnel, as it should be.