My OS is RedHat 9
the installation script of my VPN client wants to know:
In order to build the VPN kernel module, you must have the
kernel headers for the version of the kernel you are running.
For RedHat 6.x users these files are installed in /usr/src/linux by default
For RedHat 7.x users these files are installed in /usr/src/linux-2.4 by default
For Suse 7.3 users these files are installed in /usr/src/linux-2.4.10.SuSE by de
Directory containing linux kernel source code 
now, which directory does (should) contain the kernel header files?