Добрый день.

Система перезагружается самостоятельно. В логах каждый раз пишет

ct 25 16:48:17   pptp[1071]: anon log[main:pptp.c:276]: The synchronous pptp option is NOT activated
Oct 25 16:48:17   pptp[1074]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 1 'Start-Control-Connection-Request'
Oct 25 16:48:17   pptp[1074]: anon log[ctrlp_disp:pptp_ctrl.c:740]: Received Start Control Connection Reply
Oct 25 16:48:17   pptp[1074]: anon log[ctrlp_disp:pptp_ctrl.c:774]: Client connection established.
Oct 25 16:48:18   pptp[1074]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 7 'Outgoing-Call-Request'
Oct 25 16:48:18   pptp[1074]: anon log[ctrlp_disp:pptp_ctrl.c:859]: Received Outgoing Call Reply.
Oct 25 16:48:18   pptp[1074]: anon log[ctrlp_disp:pptp_ctrl.c:898]: Outgoing call established (call ID 0, peer's call ID 39808).
Oct 25 16:48:40   pptp[1153]: anon log[main:pptp.c:276]: The synchronous pptp option is NOT activated
Oct 25 16:48:40   pptp[1156]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 1 'Start-Control-Connection-Request'
Oct 25 16:48:40   pptp[1156]: anon log[ctrlp_disp:pptp_ctrl.c:740]: Received Start Control Connection Reply
Oct 25 16:48:40   pptp[1156]: anon log[ctrlp_disp:pptp_ctrl.c:774]: Client connection established.
Oct 25 16:48:41   pptp[1156]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 7 'Outgoing-Call-Request'
Oct 25 16:48:41   pptp[1156]: anon log[ctrlp_disp:pptp_ctrl.c:859]: Received Outgoing Call Reply.
Oct 25 16:48:41   pptp[1156]: anon log[ctrlp_disp:pptp_ctrl.c:898]: Outgoing call established (call ID 0, peer's call ID 39552).
Oct 25 16:48:44   pptp[1216]: anon warn[decaps_hdlc:pptp_gre.c:197]: short read (0): Invalid argument
Oct 25 16:48:44   pptp[1156]: anon log[callmgr_main:pptp_callmgr.c:231]: Closing connection (unhandled)
Oct 25 16:48:44   pptp[1156]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 12 'Call-Clear-Request'
Oct 25 16:48:44   pptp[1156]: anon log[call_callback:pptp_callmgr.c:78]: Closing connection (call state)
Oct 25 16:49:19   pptp[1074]: anon log[logecho:pptp_ctrl.c:678]: Echo Reply received.
Oct 25 16:50:19   pptp[1074]: anon log[logecho:pptp_ctrl.c:678]: Echo Reply received.
Oct 25 16:52:22   last message repeated 2 times
Oct 25 16:56:04   syslogd: kernel boot file is /boot/kernel/kernel

Происходит это пару раз за день, в основном при нагрузке на сервер, natd(при скачке файлов с локалки) или smbd(при закачивании файлов на самбу). Нагрузка pptp-client маловероятна, поскольку канал примерно 512k. Поверх pptp поднимается openvpn с шифрованием.
Система:
FreeBSD 6.2-RELEASE
CPU: Intel(R) Celeron(TM) CPU                1100MHz (1101.94-MHz 686-class CPU)
  Origin = "GenuineIntel"  Id = 0x6b1  Stepping = 1
  Features=0x383f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,MMX,FXSR,SSE>
real memory  = 671023104 (639 MB)
avail memory = 651522048 (621 MB)

Подскажите пожалуйста как установить причину?