[Sysadmins] GRE: Bad checksum from pppd

[Serge]

Здравствуйте!
в логах при подключении клиента к vpn получаю: 
GRE: Bad checksum from pppd.
CTRL: Ignored a SET LINK INFO packet with real ACCMs!

в чем проблемма и как ее решить?

Выдержка из логов:
Nov  8 19:22:58 ns pptpd[31440]: CTRL: Starting call (launching pppd, opening 
GRE)
Nov  8 19:22:58 ns pppd[31441]: Plugin radius.so loaded.
Nov  8 19:22:58 ns pppd[31441]: RADIUS plugin initialized.
Nov  8 19:22:58 ns pppd[31441]: Plugin radattr.so loaded.
Nov  8 19:22:58 ns pppd[31441]: RADATTR plugin initialized.
Nov  8 19:22:58 ns pppd[31441]: Plugin /usr/lib64/pptpd/pptpd-logwtmp.so 
loaded.
Nov  8 19:22:58 ns pppd[31441]: pppd 2.4.4 started by root, uid 0
Nov  8 19:22:58 ns pppd[31441]: Using interface ppp1
Nov  8 19:22:58 ns pppd[31441]: Connect: ppp1 <--> /dev/pts/2
Nov  8 19:22:58 ns pptpd[31440]: GRE: Bad checksum from pppd.
Nov  8 19:23:00 ns pptpd[31440]: CTRL: Ignored a SET LINK INFO packet with 
real ACCMs!
Nov  8 19:23:00 ns pppd[31441]: MPPE 128-bit stateless compression enabled


Дистрибутив Server 4.0 + Branch

freeradius-sqlcounter-1.1.7-alt2
freeradius-1.1.7-alt2
freeradius-mysql-1.1.7-alt2
pptpd-1.3.4-alt1
ppp-radius-2.4.4-alt7
ppp-2.4.4-alt7