Кратко, проблема ниже:

root@vit:~/note# pptp --version
pptp version 1.7.2

root@vit:~/note# lsmod | grep ppp
ppp_mppe                6368  0
ppp_async               8860  0
crc_ccitt               1852  1 ppp_async

root@vit:~/note# uname -r
2.6.31-14-generic

1)
root@vit:~/note# cat /etc/ppp/peers/tiger
pty "pptp tiger.host.net --nolaunchpppd"
file /etc/ppp/options.pptp
remotename PPTP
deflate 0
lcp-echo-failure 4
lcp-echo-interval 15

2)
root@vit:~/note# cat /etc/ppp/options.pptp
lock
debug
refuse-pap
refuse-eap
refuse-chap
refuse-mschap
nobsdcomp
nodeflate
require-mppe-128
require-mschap-v2

3)
root@vit:~/note# pon tiger debug dump logfd 2 nodetach
pppd options in effect:
debug debug        # (from command line)
nodetach        # (from command line)
logfd 2        # (from command line)
dump        # (from command line)
require-mschap-v2        # (from /etc/ppp/options.pptp)
refuse-pap        # (from /etc/ppp/options.pptp)
refuse-chap        # (from /etc/ppp/options.pptp)
refuse-mschap        # (from /etc/ppp/options.pptp)
refuse-eap        # (from /etc/ppp/options.pptp)
remotename PPTP        # (from /etc/ppp/peers/tiger)
        # (from /etc/ppp/options.pptp)
pty pptp tiger.host.net --nolaunchpppd        # (from /etc/ppp/peers/tiger)
crtscts        # (from /etc/ppp/options)
        # (from /etc/ppp/options)
asyncmap 0        # (from /etc/ppp/options)
lcp-echo-failure 4        # (from /etc/ppp/peers/tiger)
lcp-echo-interval 15        # (from /etc/ppp/peers/tiger)
hide-password        # (from /etc/ppp/options)
proxyarp        # (from /etc/ppp/options)
nobsdcomp        # (from /etc/ppp/options.pptp)
deflate 0        # (from /etc/ppp/peers/tiger)
require-mppe-128        # (from /etc/ppp/options.pptp)
noipx        # (from /etc/ppp/options)
using channel 69
Using interface ppp0
Connect: ppp0 <--> /dev/pts/6
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <auth chap MS-v2> <magic 0xa77e42c8> <pcomp> <accomp>]
rcvd [LCP ConfReq id=0x1 <asyncmap 0x0> <auth chap MS-v2> <magic 0x25a17196> <pcomp> <accomp>]
No auth is possible
sent [LCP ConfRej id=0x1 <auth chap MS-v2>]
rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <auth chap MS-v2> <magic 0xa77e42c8> <pcomp> <accomp>]
rcvd [LCP ConfReq id=0x2 <asyncmap 0x0> <magic 0x25a17196> <pcomp> <accomp>]
sent [LCP ConfAck id=0x2 <asyncmap 0x0> <magic 0x25a17196> <pcomp> <accomp>]
sent [LCP EchoReq id=0x0 magic=0xa77e42c8]
sent [CHAP Challenge id=0xa <a91e87bf59b36deb5f4640dd654f7152>, name = "vit"]
rcvd [LCP TermReq id=0x3 "peer refused to authenticate"]
LCP terminated by peer (peer refused to authenticate)
sent [LCP TermAck id=0x3]
Script pptp tiger.host.net --nolaunchpppd finished (pid 30698), status = 0x0
Modem hangup
Connection terminated.

=========

Логи на стороне сервера:

# less  /var/log/pppd.log
------------------------------------------------
Plugin /usr/lib/pppd/2.4.4/radius.so loaded.
RADIUS plugin initialized.
using channel 104
Using interface ppp1
Connect: ppp1 <--> /dev/pts/8
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <auth chap MS-v2> <magic 0x25a17196> <pcomp> <accomp>]
rcvd [LCP ConfReq id=0x1 <asyncmap 0x0> <auth chap MS-v2> <magic 0xa77e42c8> <pcomp> <accomp>]
sent [LCP ConfAck id=0x1 <asyncmap 0x0> <auth chap MS-v2> <magic 0xa77e42c8> <pcomp> <accomp>]
rcvd [LCP ConfRej id=0x1 <auth chap MS-v2>]
sent [LCP ConfReq id=0x2 <asyncmap 0x0> <magic 0x25a17196> <pcomp> <accomp>]
rcvd [LCP ConfAck id=0x2 <asyncmap 0x0> <magic 0x25a17196> <pcomp> <accomp>]
peer refused to authenticate: terminating link
sent [LCP TermReq id=0x3 "peer refused to authenticate"]
rcvd [LCP EchoReq id=0x0 magic=0xa77e42c8]
rcvd [CHAP Challenge id=0xa <a91e87bf59b36deb5f4640dd654f7152>, name = "vit"]
Discarded non-LCP packet when LCP not open
rcvd [LCP TermAck id=0x3]
Connection terminated.

-------------
# egrep '^[^#]'  /etc/ppp/options.pptpd
lock
debug
name pptpd
nodeflate
nobsdcomp
nodetach
auth
-pap
-chap
-mschap
+mschap-v2
require-mppe-128
logfile /var/log/pppd.log
ms-dns 172.20.0.25
plugin /usr/lib/pppd/2.4.4/radius.so

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Спасибо за внимание.