PPTP-VPN von Ubuntu kann keine Verbindung herstellen

Ich versuche, unter Linux (Kubuntu 9.10) ein VPN zu konfigurieren, das ich bereits von Windows aus verwende.

Ich habe das Paket network-manager-pptp installiert und das VPN unter Network Manager hinzugefügt. Dies sind die Parameter unter der Schaltfläche "Erweitert":

• Authentifizierungsmethoden: PAP, CHAP, MSCHAP, MSCHAP2, EAP
  (Ich habe auch "MSCHAP, MSCHAP2" versucht)
• Verwenden Sie die MPPE-Verschlüsselung: Ja
• Krypto: Jeder
• Stateful-Verschlüsselung verwenden: Nein
• BSD-Komprimierung zulassen: Ja
• Deflate-Komprimierung zulassen: Ja
• TCP-Headerkomprimierung zulassen: Ja
• PPP-Echo-Pakete senden: Nein

Wenn ich versuche zu verbinden, funktioniert es nicht und das bekomme ich im Systemprotokoll:

2010-04-08 13:53:47 pcelena NetworkManager <info> Starting VPN service 'org.freedesktop.NetworkManager.pptp'... 2010-04-08 13:53:47 pcelena NetworkManager <info> VPN service 'org.freedesktop.NetworkManager.pptp' started (org.freedesktop.NetworkManager.pptp), PID 4931 2010-04-08 13:53:47 pcelena NetworkManager <info> VPN service 'org.freedesktop.NetworkManager.pptp' just appeared, activating connections 2010-04-08 13:53:47 pcelena pppd[4932] Plugin /usr/lib/pppd/2.4.5//nm-pptp-pppd-plugin.so loaded. 2010-04-08 13:53:47 pcelena NetworkManager <info> VPN plugin state changed: 3 2010-04-08 13:53:47 pcelena pppd[4932] pppd 2.4.5 started by root, uid 0 2010-04-08 13:53:47 pcelena NetworkManager <info> VPN connection 'MYVPN' (Connect) reply received. 2010-04-08 13:53:47 pcelena NetworkManager SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/ppp0, iface: ppp0) 2010-04-08 13:53:47 pcelena NetworkManager SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/ppp0, iface: ppp0): no ifupdown configuration found. 2010-04-08 13:53:47 pcelena pppd[4932] Using interface ppp0 2010-04-08 13:53:47 pcelena pppd[4932] Connect: ppp0 <--> /dev/pts/2 2010-04-08 13:53:47 pcelena pptp[4934] nm-pptp-service-4931 log[main:pptp.c:314]: The synchronous pptp option is NOT activated 2010-04-08 13:53:47 pcelena pptp[4927] nm-pptp-service-4918 log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 7 'Outgoing-Call-Request' 2010-04-08 13:53:47 pcelena pptp[4927] nm-pptp-service-4918 log[ctrlp_disp:pptp_ctrl.c:858]: Received Outgoing Call Reply. 2010-04-08 13:53:47 pcelena pptp[4927] nm-pptp-service-4918 log[ctrlp_disp:pptp_ctrl.c:897]: Outgoing call established (call ID 1, peer's call ID 14800). 2010-04-08 13:53:48 pcelena pppd[4932] CHAP authentication succeeded 2010-04-08 13:53:48 pcelena pppd[4932] CHAP authentication succeeded 2010-04-08 13:53:48 pcelena pppd[4932] LCP terminated by peer 2010-04-08 13:53:48 pcelena pptp[4927] nm-pptp-service-4918 log[ctrlp_disp:pptp_ctrl.c:929]: Call disconnect notification received (call id 14800) 2010-04-08 13:53:48 pcelena pptp[4927] nm-pptp-service-4918 log[ctrlp_disp:pptp_ctrl.c:788]: Received Stop Control Connection Request. 2010-04-08 13:53:48 pcelena pptp[4927] nm-pptp-service-4918 log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 4 'Stop-Control-Connection-Reply' 2010-04-08 13:53:48 pcelena pptp[4927] nm-pptp-service-4918 log[callmgr_main:pptp_callmgr.c:258]: Closing connection (shutdown) 2010-04-08 13:53:48 pcelena pptp[4927] nm-pptp-service-4918 log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 12 'Call-Clear-Request' 2010-04-08 13:53:48 pcelena pptp[4927] nm-pptp-service-4918 log[callmgr_main:pptp_callmgr.c:258]: Closing connection (shutdown) 2010-04-08 13:53:48 pcelena pptp[4927] nm-pptp-service-4918 log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 12 'Call-Clear-Request' 2010-04-08 13:53:48 pcelena pptp[4927] nm-pptp-service-4918 log[call_callback:pptp_callmgr.c:79]: Closing connection (call state) 2010-04-08 13:53:48 pcelena pppd[4932] Modem hangup 2010-04-08 13:53:48 pcelena pppd[4932] Connection terminated. 2010-04-08 13:53:48 pcelena NetworkManager <info> VPN plugin failed: 1 2010-04-08 13:53:48 pcelena NetworkManager SCPlugin-Ifupdown: devices removed (path: /sys/devices/virtual/net/ppp0, iface: ppp0) 2010-04-08 13:53:48 pcelena pppd[4932] Exit. 2010-04-08 13:53:48 pcelena NetworkManager <info> VPN plugin failed: 1 2010-04-08 13:53:48 pcelena NetworkManager <info> VPN plugin state changed: 6 2010-04-08 13:53:48 pcelena NetworkManager <info> VPN plugin state change reason: 0 2010-04-08 13:53:48 pcelena NetworkManager <WARN> connection_state_changed(): Could not process the request because no VPN connection was active. 2010-04-08 13:53:48 pcelena NetworkManager <info> Policy set 'Auto eth0' (eth0) as default for routing and DNS. 2010-04-08 13:54:01 pcelena NetworkManager <debug> [1270727641.001390] ensure_killed(): waiting for vpn service pid 4931 to exit 2010-04-08 13:54:01 pcelena NetworkManager <debug> [1270727641.001479] ensure_killed(): vpn service pid 4931 cleaned up 

Der Fehler, der hier hervorsticht, ist " pppd [4932] LCP von Peer beendet ".

Hat jemand einen Vorschlag, was das Problem sein kann und wie es funktioniert?