HOWTO: PPtP VPN

Edit 9/9/2012: Updated so all the instructions are up-to-date and in one place.

Be sure to download the GPL code and extract it onto your /c/ filesystem. There's not enough space to extract everything into the root filesystem, and its a good way to kill your ReadyNAS.

mkdir /c/devel
cd /c/devel
wget http://.......
mkdir (downloaded filename without zip)
unzip (downloaded file) -d (dir you just created)

after downloading the firmware run these command:

apt-get update
apt-get install build-essential
apt-get install lzma
apt-get install libncurses5-dev
apt-get install nano    <- because I'm no good with vi to edit files.

then pre-compile the current kernel

cd (unzip dir)/kernel/(kernel version)
cp defconfig.smp linux-(kernel version)/.config     <--For x86_64 systems only!
cp defconfig.up linux-(kernel version)/.config     <--For all others?
cd linux-(kernel version)
make clean

Then this is where you run the 'make menuconfig' command. (Note that you do not need to fix the "Cross Compile" configuration or copy any config files when doing this on an x86-based ReadyNAS.) The PPP options will be under Device Drivers -> Network Device Support -> PPP Support. Be sure to select

Device Drivers
  Network device support
    <M> PPP Support
      [*] PPP Filtering
      <M> PPP Support for async serial ports
      <M> PPP Support for tty ports
      <M> PPP Deflate compression
      <M> PPP BSD-Compress compression
      <M> PPP MPPE compression
      <M> PPP over Ethernet
Cryptographic API
  <M> Deflate compression algorithm       <- It's at the very bottom
  <M> Zlib compression algorithm
  <M> LZO compression algorithm

Press 'esc, esc' a few times to exit out until it prompts you to save. (yes) Then:

make modules
make modules_install

That should install the modules. If it doesn't, then you can install them manually:

cp drivers/net/*.ko /lib/modules/(kernel folder x86_64)/kernel/drivers/net/
depmod -a     <- no output indicates a success
modprobe ppp_generic     <- no output means everything worked!

Now follow the instructions, as above, to install the PPP service: viewtopic.php?f=35&t=33132&p=232929#p182215
Once you've done all that and used to start it up, if it still isn't working or doesn't work as expected, here're some extra commands to figure out exactly what might be going wrong.

tail -n30 /var/log/syslog
dmesg

If you see a problem in the logfile "unable to open /dev/ppp", then this command will help you:

mknod /dev/ppp c 108 0

If, every time after rebooting, you still have a problem with the /dev/ppp not existing, then you can add this to your /etc/init.d/pptpd file:

case "$1" in
  start)
    echo -n "Starting PPTP Daemon: "
    if [ ! -c /dev/ppp ]; then mknod /dev/ppp c 108 0; fi
    start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON \
        -- < /dev/null > /dev/null
    echo "pptpd."
    ;;

And once you get a user CONNECTED to the VPN, here's a WONDERFUL troubleshooting guide to getting traffic flowing correctly over your new VPN: http://poptop.sourceforge.net/dox/diagn ... ding.phtml
As I sit here, my iPhone is able to browse everything on my local ReadyNAS via the cellular connection.