Все оказалось даже проще чем я думал
root@slax:/etc/ppp# cat /etc/ppp/options
name skivan
remotename vpn
defaultroute
refuse-eap
require-chap
noauth
asyncmap 0
crtscts
lock
hide-password
local
noproxyarp
lcp-echo-interval 30
lcp-echo-failure 4
noipx
root@slax:/etc/ppp# cat /etc/ppp/chap-secrets
skivan vpn super_pass *
root@slax:/etc/ppp# pptp unlim.tomsk.ru
root@slax:/etc/ppp# ping
www.ya.ru -I ppp0
PING ya.ru (213.180.204.

from 192.168.2.19 ppp0: 56(84) bytes of data.
64 bytes from ya.ru (213.180.204.

: icmp_seq=1 ttl=58 time=96.1 ms
64 bytes from ya.ru (213.180.204.

: icmp_seq=2 ttl=58 time=114 ms
64 bytes from ya.ru (213.180.204.

: icmp_seq=3 ttl=58 time=113 ms
64 bytes from ya.ru (213.180.204.

: icmp_seq=4 ttl=58 time=103 ms
64 bytes from ya.ru (213.180.204.

: icmp_seq=5 ttl=58 time=106 ms