SuSE 6.1 / pppd

Hi,
ich habe folgendes Problem:
Ich habe einen alten 386er mit SuSE Linux 6.1 installiert und will in als Router bzw. Firewall einsetzen. Ich muß dazusagen, dass die Firewall noch nicht läuft (daran liegt mein Problem also nicht).
Wenn ich mit einen ppp-up script per pppd eine Modemverbindung aufbauen will, klappt das prinzipiell und es kommt eine Verbindung zustande, alerdings legt das Modem oder was weiß ich was sofort wieder auf. Unter /var/log/messages kann ich folgende Meldung lesen (aber nicht smit anfangen):

Jan 29 21:10:51 Firewall pppd[304]: Serial connection established.
Jan 29 21:10:52 Firewall pppd[304]: Using interface ppp0
Jan 29 21:10:52 Firewall pppd[304]: Connect: ppp0 <--> /dev/ttyS0
Jan 29 21:10:52 Firewall pppd[304]: sent [LCP ConfReq id=0x1 <auth chap 05> <mag
ic 0x91234354> <pcomp> <accomp>]
Jan 29 21:10:55 Firewall pppd[304]: sent [LCP ConfReq id=0x1 <auth chap 05> <mag
ic 0x91234354> <pcomp> <accomp>]
Jan 29 21:10:55 Firewall pppd[304]: rcvd [LCP ConfReq id=0x3f <asyncmap 0xa0000>
<auth chap 05> <magic 0x6aae0313> <pcomp> <accomp>]
Jan 29 21:10:55 Firewall pppd[304]: sent [LCP ConfRej id=0x3f <auth chap 05>]
Jan 29 21:10:55 Firewall pppd[304]: rcvd [LCP ConfAck id=0x1 <auth chap 05> <mag
ic 0x91234354> <pcomp> <accomp>]
Jan 29 21:10:55 Firewall pppd[304]: rcvd [LCP ConfReq id=0x40 <asyncmap 0xa0000>
<auth pap> <magic 0x6aae0313> <pcomp> <accomp>]
Jan 29 21:10:55 Firewall pppd[304]: sent [LCP ConfRej id=0x40 <auth pap>]
Jan 29 21:10:56 Firewall pppd[304]: rcvd [LCP ConfReq id=0x41 <asyncmap 0xa0000>
<auth chap 80> <magic 0x6aae0313> <pcomp> <accomp>]
Jan 29 21:10:56 Firewall pppd[304]: sent [LCP ConfRej id=0x41 <auth chap 80>]
Jan 29 21:10:56 Firewall pppd[304]: rcvd [LCP ConfReq id=0x42 <asyncmap 0xa0000>
<auth chap 05> <magic 0x6aae0313> <pcomp> <accomp>]
Jan 29 21:10:56 Firewall pppd[304]: sent [LCP ConfRej id=0x42 <auth chap 05>]
Jan 29 21:10:56 Firewall pppd[304]: rcvd [LCP ConfReq id=0x43 <asyncmap 0xa0000>
<auth pap> <magic 0x6aae0313> <pcomp> <accomp>]
Jan 29 21:10:56 Firewall pppd[304]: sent [LCP ConfRej id=0x43 <auth pap>]
Jan 29 21:10:56 Firewall pppd[304]: rcvd [LCP ConfReq id=0x44 <asyncmap 0xa0000>
<auth chap 80> <magic 0x6aae0313> <pcomp> <accomp>]
Jan 29 21:10:56 Firewall pppd[304]: sent [LCP ConfRej id=0x44 <auth chap 80>]
Jan 29 21:10:56 Firewall pppd[304]: rcvd [LCP ConfReq id=0x45 <asyncmap 0xa0000>
<auth chap 05> <magic 0x6aae0313> <pcomp> <accomp>]
Jan 29 21:10:56 Firewall pppd[304]: sent [LCP ConfRej id=0x45 <auth chap 05>]
Jan 29 21:10:56 Firewall pppd[304]: rcvd [LCP ConfReq id=0x46 <asyncmap 0xa0000>
<auth pap> <magic 0x6aae0313> <pcomp> <accomp>]
Jan 29 21:10:56 Firewall pppd[304]: sent [LCP ConfRej id=0x46 <auth pap>]
Jan 29 21:10:56 Firewall pppd[304]: rcvd [LCP ConfReq id=0x47 <asyncmap 0xa0000>
<auth chap 80> <magic 0x6aae0313> <pcomp> <accomp>]
Jan 29 21:10:56 Firewall pppd[304]: sent [LCP ConfRej id=0x47 <auth chap 80>]
Jan 29 21:10:56 Firewall pppd[304]: rcvd [LCP ConfReq id=0x48 <asyncmap 0xa0000>
<auth chap 05> <magic 0x6aae0313> <pcomp> <accomp>]
Jan 29 21:10:56 Firewall pppd[304]: sent [LCP ConfRej id=0x48 <auth chap 05>]
Jan 29 21:10:56 Firewall pppd[304]: rcvd [LCP ConfReq id=0x49 <asyncmap 0xa0000>
<auth pap> <magic 0x6aae0313> <pcomp> <accomp>]
Jan 29 21:10:56 Firewall pppd[304]: sent [LCP ConfRej id=0x49 <auth pap>]
Jan 29 21:10:57 Firewall pppd[304]: rcvd [LCP TermReq id=0x4a]
Jan 29 21:10:57 Firewall pppd[304]: sent [LCP TermAck id=0x4a]
Jan 29 21:10:57 Firewall pppd[304]: Modem hangup
Jan 29 21:10:57 Firewall pppd[304]: Connection terminated.
Jan 29 21:10:58 Firewall pppd[304]: Exit.

Vielen Dank im Voraus, ich hoffe ihr wißt da Bescheid.

Timo