I have been playing with this for some time .. Below are patches over Cisco VPN client 4.8 rev 490 some are compiled from around and some are my own ports (especially for 2.6.24+ ):
For 2.6.18 based kernels (OEL/RHEL/CentOS 5), download and apply vpnclient-4.8-2.6.18-XceptN.patch on your vpnclient build directory. e.g.:
# wget -q http://xceptn.com/patches/vpnclient/vpnclient-4.8-2.6.18-XceptN.patch
# cd vpnclient
# patch < ../vpnclient-4.8-2.6.18-XceptN.patch
For 2.6.24/25 (Fedora 8, 9 (Beta)) series I have used vpnclient-4.8-2.6.25-XceptN.patch. e.g.:
# wget http://xceptn.com/patches/vpnclient/vpnclient-4.8-2.6.25-XceptN.patch
# cd vpnclient
# patch < ../vpnclient-4.8-2.6.25-XceptN.patch
The patches are just dirty workarounds. But they work well 🙂