How to install Cisco VPN client on Ubuntu Hardy Heron 8.04 64 bit


Nov 20 2010: New guide for Cisco vpnclient on Ubuntu linux Maverick Meerkat 10.10

UPDATE: A new client for linux ( is out. You no longer need the patch for 2.6.24+ kernel (vpnclient-linux-2.6.24-final.diff). However the patch for 64 bit systems is still required and the CFLAGS variable in Makefile still need to be changed to EXTRA_CFLAGS.

June 26 2009: This post also applies to Ubuntu Jaunty Jackalope 9.04 (more than one year later and it’s still not fixed)

I assume that you have the latest version and the required packages for compiling.

If you install the original Cisco VPN client on Hardy you will receive the following error:

make -C /lib/modules/2.6.24-16-generic/build SUBDIRS=/home/lamnk/src/vpn/vpnclient modules
make[1]: Entering directory `/usr/src/linux-headers-2.6.24-16-generic’
scripts/ *** CFLAGS was changed in “/home/lamnk/src/vpn/vpnclient/Makefile”. Fix it to use EXTRA_CFLAGS. Stop.
make[1]: *** [_module_/home/lamnk/src/vpn/vpnclient] Error 2
make[1]: Leaving directory `/usr/src/linux-headers-2.6.24-16-generic’
make: *** [default] Error 2

As those lines point out, you need to edit the Makefile file in the vpnclient folder and change CFLAGS to EXTRA_CFLAGS: Change the following line in Makefile

CFLAGS += -mcmodel=kernel -mno-red-zone


EXTRA_CFLAGS += -mcmodel=kernel -mno-red-zone

then apply the 2 patches for kernel 2.6.24 and for 64 bit:

vpnclient_folder$ wget

vpnclient_folder$ wget

vpnclient_folder$ patch < ./vpnclient-linux-2.6.24-final.diff

vpnclient_folder$ patch < ./cisco_skbuff_offset.patch

vpnclient_folder$ ./vpn_install

If your system is 32 bit then you only need to patch the vpnclient-linux-2.6.24-final.diff file.

The patch for 64 bit system is from Stephen Frost and the patch for kernel 2.6.24 is from Alexander Griesser. Seriously Cisco should pay those guys some money … If these patches help you then please consider donate them.

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