Проблемма с ppp

Иногда в message.log выдается подобная вещь: ifup-ppp: pppd started for ppp0 on /dev/ttyS0 at 115200 pppd[5286]: The remote system (ppp0) is required to authenticate itself but I server pppd[5286]: couldn't find any suitable secret (password)for it to use to do so. и коннекта нету никакого