MPPE Encryption HOWTO OS: Linux - Debian Woody Files Needed.
ppp v2.4.2
linux kernel (I used 2.4.25)
libpcap development files
ppp-2.4.2 mppe patch.
gcc-2.95 and make etc, all the tools to build a kernel.
apt-get install libpcap-dev
cd /usr/src/
wget 
http://ccache.samba.org/ftp/ppp/ppp-2.4.2.tar.gz
wget http://www.kernel.org/pub/linux/kernel/v2.4/linux-2.4.25.tar.bz2
wget http://pptpclient.sourceforge.net/mppe/ppp-2.4.2_cvs20040216-linux-mppe.tar.gz
tar -zxf ppp-2.4.2.tar.gz
tar -jxf linux-2.4.25.tar.bz2
tar -zxf ppp-2.4.2_cvs20040216-linux-mppe.tar.gz
If you like you can symlink /usr/src/linux to /usr/src/linux-2.4.25/ This is usefull because some things that require kernel source to build look here for it.
ln -s /usr/src/linux-2.4.25 /usr/src/linux
cd ppp-2.4.2_cvs20040216-linux-mppe/
./mppeinstall.sh /usr/src/linux-2.4.25/
cd ../linux-2.4.25/
make menuconfig (or whatever way you prefer to set up your kernel config) Build support for all ppp related modules as modules, It will fail for some unknown reason if you dont compile as a module.
build the kernel and modules as usual, install it and reboot. Dont forget to run lilo or whatever. Fixing up a broken kernel build is beyond the scope of this document. For now I'll assume that all has been sucessfull and you are running your new kernel.
cd /usr/src/ppp-2.4.2/ ./configure make make install
Your ppp should now have support for mppe encryption a quick test to see if pppd is ready.
strings /usr/sbin/pppd |grep mppe
next load the kernel support modprobe ppp_mppe to make it easier put these into /etc/modules or add these lines to /etc/modules.conf
alias ppp-compress-18 ppp_mppe alias ppp-compress-21 bsd_comp alias ppp-compress-24 ppp_deflate alias ppp-compress-26 ppp_deflate
This should make them load automaticly when they are needed.
Now configure your pptp connections, or whatever you needed this support for.
One page links to MPPEKernelHowto:
