How to add route to VTUN that use PPP interface.

in /etc/vtund.conf  for client..

ultramankosmos {
passwd makan2;
type tty;
proto tcp;
keepalive yes;
persist yes;
multi killold;
up {
ppp "noipdefault lcp-echo-interval 60 lcp-echo-failure 3 nodefaultroute ipparam IMTHEVPN";
};
down{
route "del 192.168.171.1";
};
}

then.

in /etc/ppp/ip-preup

logger NAMRAN::I got $5 $6
if [[ "$6" =~ IMTHEVPN ]]
then
logger NAMRAN::$6 going to route to...$5
/sbin/route add -host 192.168.171.1 gw $5
else
logger NAMRAN:: doing nothing
fi

verify .. use

netstat -rn

after it come up..