最近我安装了 ubuntu 12.04 LTS；
我在通过 pptp 客户端连接互联网时遇到问题。我将连接到我大学的无线连接，然后是 pppoe 连接，然后是 pptp 来访问互联网。
我成功连接到 wifi 和 pppoe，这是我可以访问学院网站的唯一方式。然后我连接到 pptp，但我失去了所有的互联网访问权限（ping和浏览）；
这是我的ifconfig结果：
ppp0 Link encap:Point-to-Point Protocol
inet addr:192.168.11.37 P-t-P:192.168.11.10 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1488 Metric:1
RX packets:297 errors:0 dropped:0 overruns:0 frame:0
TX packets:374 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:23812 (23.8 KB) TX bytes:26959 (26.9 KB)
ppp1 Link encap:Point-to-Point Protocol
inet addr:176.102.250.25 P-t-P:176.102.224.55 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1408 Metric:1
RX packets:169 errors:0 dropped:0 overruns:0 frame:0
TX packets:173 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:10241 (10.2 KB) TX bytes:10541 (10.5 KB)
wlan0 Link encap:Ethernet HWaddr 20:7c:8f:3b:f0:ee
inet addr:192.168.193.154 Bcast:192.168.193.255 Mask:255.255.255.0
inet6 addr: fe80::227c:8fff:fe3b:f0ee/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:13292 errors:0 dropped:3 overruns:0 frame:0
TX packets:1243 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:2158036 (2.1 MB) TX bytes:160543 (160.5 KB)
我的route -n结果：
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 0.0.0.0 0.0.0.0 U 0 0 0 ppp1
0.0.0.0 0.0.0.0 0.0.0.0 U 0 0 0 ppp0
176.102.224.55 0.0.0.0 255.255.255.255 UH 0 0 0 ppp1
192.168.11.10 0.0.0.0 255.255.255.255 UH 0 0 0 ppp0
192.168.100.55 0.0.0.0 255.255.255.255 UH 0 0 0 ppp0
192.168.193.0 0.0.0.0 255.255.255.0 U 0 0 0 wlan0
ppp0 用于 pppoe，ppp1 用于 pptp，wlan0 用于我的无线
我的syslog节目：
Aug 2 12:34:17 fman-Q1585M avahi-daemon[861]: Joining mDNS multicast group on interface wlan0.IPv4 with address 192.168.193.154.
Aug 2 12:34:17 fman-Q1585M avahi-daemon[861]: New relevant interface wlan0.IPv4 for mDNS.
Aug 2 12:34:17 fman-Q1585M avahi-daemon[861]: Registering new address record for 192.168.193.154 on wlan0.IPv4.
Aug 2 12:34:17 fman-Q1585M kernel: [ 940.384157] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
Aug 2 12:35:02 fman-Q1585M kernel: [ 984.933056] wlan0: authenticate with 00:15:6d:f8:09:6d
Aug 2 12:35:02 fman-Q1585M kernel: [ 984.953053] wlan0: send auth to 00:15:6d:f8:09:6d (try 1/3)
Aug 2 12:35:02 fman-Q1585M kernel: [ 984.956477] wlan0: authenticated
Aug 2 12:35:02 fman-Q1585M kernel: [ 984.968881] wlan0: associate with 00:15:6d:f8:09:6d (try 1/3)
Aug 2 12:35:02 fman-Q1585M kernel: [ 984.977656] wlan0: RX AssocResp from 00:15:6d:f8:09:6d (capab=0x421 status=0 aid=7)
Aug 2 12:35:02 fman-Q1585M kernel: [ 984.978665] wlan0: associated
Aug 2 12:35:02 fman-Q1585M kernel: [ 984.978968] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
Aug 2 12:35:04 fman-Q1585M avahi-daemon[861]: Joining mDNS multicast group on interface wlan0.IPv6 with address fe80::227c:8fff:fe3b:f0ee.
Aug 2 12:35:04 fman-Q1585M avahi-daemon[861]: New relevant interface wlan0.IPv6 for mDNS.
Aug 2 12:35:04 fman-Q1585M avahi-daemon[861]: Registering new address record for fe80::227c:8fff:fe3b:f0ee on wlan0.*.
Aug 2 12:35:33 fman-Q1585M dhclient: DHCPREQUEST of 192.168.193.154 on wlan0 to 255.255.255.255 port 67
Aug 2 12:35:33 fman-Q1585M dhclient: DHCPACK of 192.168.193.154 from 192.168.189.2
Aug 2 12:35:33 fman-Q1585M dhclient: bound to 192.168.193.154 -- renewal in 33990 seconds.
Aug 2 12:36:06 fman-Q1585M pppd[2908]: Plugin rp-pppoe.so loaded.
Aug 2 12:36:06 fman-Q1585M pppd[2910]: pppd 2.4.5 started by root, uid 0
Aug 2 12:36:06 fman-Q1585M pppd[2910]: PPP session is 1513
Aug 2 12:36:06 fman-Q1585M pppd[2910]: Connected to d4:ca:6d:89:1d:fa via interface wlan0
Aug 2 12:36:06 fman-Q1585M pppd[2910]: Using interface ppp0
Aug 2 12:36:06 fman-Q1585M pppd[2910]: Connect: ppp0 <--> wlan0
Aug 2 12:36:06 fman-Q1585M NetworkManager[866]: SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/ppp0, iface: ppp0)
Aug 2 12:36:06 fman-Q1585M NetworkManager[866]: SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/ppp0, iface: ppp0): no ifupdown configuration found.
Aug 2 12:36:06 fman-Q1585M pppd[2910]: Remote message: Login ok
Aug 2 12:36:06 fman-Q1585M pppd[2910]: PAP authentication succeeded
Aug 2 12:36:06 fman-Q1585M pppd[2910]: peer from calling number D4:CA:6D:89:1D:FA authorized
Aug 2 12:36:06 fman-Q1585M pppd[2910]: replacing old default route to wlan0 [192.168.193.10]
Aug 2 12:36:06 fman-Q1585M pppd[2910]: local IP address 192.168.11.77
Aug 2 12:36:06 fman-Q1585M pppd[2910]: remote IP address 192.168.11.10
Aug 2 12:36:06 fman-Q1585M pppd[2910]: primary DNS address 192.168.100.6
Aug 2 12:36:06 fman-Q1585M pppd[2910]: CCP terminated by peer (No compression negotiated^@)
Aug 2 12:36:06 fman-Q1585M pppd[2910]: Compression disabled by peer.
Aug 2 12:36:26 fman-Q1585M pppd[2948]: pppd 2.4.5 started by root, uid 0
Aug 2 12:36:26 fman-Q1585M pppd[2948]: Using interface ppp1
Aug 2 12:36:26 fman-Q1585M pppd[2948]: Connect: ppp1 <--> /dev/pts/1
Aug 2 12:36:26 fman-Q1585M NetworkManager[866]: SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/ppp1, iface: ppp1)
Aug 2 12:36:26 fman-Q1585M NetworkManager[866]: SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/ppp1, iface: ppp1): no ifupdown configuration found.
Aug 2 12:36:26 fman-Q1585M pptp[2950]: anon log[main:pptp.c:314]: The synchronous pptp option is NOT activated
Aug 2 12:36:26 fman-Q1585M pptp[2958]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 1 'Start-Control-Connection-Request'
Aug 2 12:36:26 fman-Q1585M pptp[2958]: anon log[ctrlp_disp:pptp_ctrl.c:739]: Received Start Control Connection Reply
Aug 2 12:36:26 fman-Q1585M pptp[2958]: anon log[ctrlp_disp:pptp_ctrl.c:773]: Client connection established.
Aug 2 12:36:27 fman-Q1585M pptp[2958]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 7 'Outgoing-Call-Request'
Aug 2 12:36:27 fman-Q1585M pptp[2958]: anon log[ctrlp_disp:pptp_ctrl.c:858]: Received Outgoing Call Reply.
Aug 2 12:36:27 fman-Q1585M pptp[2958]: anon log[ctrlp_disp:pptp_ctrl.c:897]: Outgoing call established (call ID 0, peer's call ID 31649).
Aug 2 12:36:28 fman-Q1585M pppd[2948]: CHAP authentication succeeded
Aug 2 12:36:28 fman-Q1585M pppd[2948]: MPPE 128-bit stateless compression enabled
Aug 2 12:36:29 fman-Q1585M pppd[2948]: local IP address 176.102.250.111
Aug 2 12:36:29 fman-Q1585M pppd[2948]: remote IP address 176.102.224.55
Aug 2 12:37:27 fman-Q1585M pptp[2958]: anon log[logecho:pptp_ctrl.c:677]: Echo Reply received.
Aug 2 12:38:27 fman-Q1585M pptp[2958]: anon log[logecho:pptp_ctrl.c:677]: Echo Reply received.
Aug 2 12:39:27 fman-Q1585M pptp[2958]: anon log[logecho:pptp_ctrl.c:677]: Echo Reply received.
Aug 2 12:40:27 fman-Q1585M pptp[2958]: anon log[logecho:pptp_ctrl.c:677]: Echo Reply received.
Aug 2 12:41:27 fman-Q1585M pptp[2958]: anon log[logecho:pptp_ctrl.c:677]: Echo Reply received.
Aug 2 12:42:27 fman-Q1585M pptp[2958]: anon log[logecho:pptp_ctrl.c:677]: Echo Reply received.
Aug 2 12:43:27 fman-Q1585M pptp[2958]: anon log[logecho:pptp_ctrl.c:677]: Echo Reply received.
Aug 2 12:44:27 fman-Q1585M pptp[2958]: anon log[logecho:pptp_ctrl.c:677]: Echo Reply received.
Aug 2 12:45:27 fman-Q1585M pptp[2958]: anon log[logecho:pptp_ctrl.c:677]: Echo Reply received.
Aug 2 12:46:27 fman-Q1585M pptp[2958]: anon log[logecho:pptp_ctrl.c:677]: Echo Reply received.
Aug 2 12:46:27 fman-Q1585M pptp[2958]: anon log[logecho:pptp_ctrl.c:679]: no more Echo Reply/Request packets will be reported.
Aug 2 13:17:01 fman-Q1585M CRON[3498]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Aug 2 13:18:15 fman-Q1585M pptp[3392]: anon log[pptp_handle_timer:pptp_ctrl.c:1050]: closing control connection due to missing echo reply
Aug 2 13:18:15 fman-Q1585M pptp[3392]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 12 'Call-Clear-Request'
Aug 2 13:18:15 fman-Q1585M pptp[3392]: anon log[pptp_conn_close:pptp_ctrl.c:430]: Closing PPTP connection
Aug 2 13:18:15 fman-Q1585M pptp[3392]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 3 'Stop-Control-Connection-Request'
Aug 2 13:18:15 fman-Q1585M pptp[3392]: anon log[call_callback:pptp_callmgr.c:79]: Closing connection (call state)
Aug 2 13:18:15 fman-Q1585M pppd[3382]: Modem hangup
Aug 2 13:18:15 fman-Q1585M pppd[3382]: Connect time 24.0 minutes.
Aug 2 13:18:15 fman-Q1585M pppd[3382]: Sent 909838891 bytes, received 12167 bytes.
Aug 2 13:18:15 fman-Q1585M pppd[3382]: MPPE disabled
Aug 2 13:18:15 fman-Q1585M pppd[3382]: Connection terminated.
Aug 2 13:18:15 fman-Q1585M avahi-daemon[861]: Withdrawing workstation service for ppp1.
Aug 2 13:18:15 fman-Q1585M NetworkManager[866]: SCPlugin-Ifupdown: devices removed (path: /sys/devices/virtual/net/ppp1, iface: ppp1)
Aug 2 13:18:16 fman-Q1585M pppd[3382]: Exit.