[It seems that here the VPN doesn't require support for this, because my module isn't loaded at run time with all the others, but the connection goes..So skip point 3 of the mini-HOWTO for the moment..]
MPPE stands for Microsoft Point to Point Encryption. Download the package 'ppp-mppe' (dont' care if the version sounds older then the one of pppd) and afterwards do the following to install it:
cd /usr/src/archive/im
tar xzvf ppp-mppe-2.4.0-4.tar.gz
cd ppp-mppe-2.4.0-4
chmod u+x unpack.sh
./unpack.sh
cd ppp-2.4.0
./configure
make
Now let's save original PPP programs from your Linux distribution (please note that your distribution might place these files in different directories).
cp /usr/sbin/chat /usr/sbin/chat.bak
cp /usr/sbin/pppd /usr/sbin/pppd.bak
cp /usr/sbin/pppdump /usr/sbin/pppdump.bak
cp /usr/sbin/pppstats /usr/sbin/pppstats.bak
And, now install the new versions of PPPd:
make install
cd linux-kernel
NOTE: When compiling the MPPE kernel module:
The makefile's auto kernel-tree mechanism could be broken in yuor source-package. To fix things, you have to do the following (these steps assume that your linux source tree is in "/usr/src/kernel/linux" as usual):
edit the "kmodbuild.sh" script, look for the "ARGS" line and change it so that it is:
ARGS="TREE=/usr/src/kernel/linux"
Now compile the kernel module:
./kmodbuild.sh
The final compile output from the above step should look something like:
There is a script in kernel-modules that can do this for you. To use it to
install your newly built kernel modules, type:
kernel-modules/kmodinst.sh kernel-modules/new-2.4.18
Check the bottom line displayed on your system when you ran the "./kmodbuild.sh" script. The name of the directory will be different from the one displayed below depending on the kernel version installed on your machine.
From the message received from above, run the following command for a generic 2.4.18 kernel:
kernel-modules/kmodinst.sh kernel-modules/new-2.4.18
NOTE:
I tested this script with kernels 2.4.18 and 2.4.19, and everything went fine.