Linux PPP：如何调试退出代码 = 16 的断开连接？

Question

我在我的 ARM Linux 嵌入式系统上使用pppd和wvdial。我有一个通过串行端口连接的 CDMA 调制解调器，并且正在连接到 Verizon 网络。我看到每天pppd有几次退出，退出代码为 16（请参阅下面日志中的确切消息）。我如何找出导致这些断开连接的原因？特别是该LCP terminated by peer消息表明了什么？

Feb 18 12:31:04 ts7600-47aad3 pppd[3242]: LCP terminated by peer
Feb 18 12:31:04 ts7600-47aad3 pppd[3242]: Connect time 0.6 minutes.
Feb 18 12:31:04 ts7600-47aad3 pppd[3242]: Sent 1044 bytes, received 0 bytes.
Feb 18 12:31:04 ts7600-47aad3 pppd[3242]: restoring old default route to eth0 [1
92.168.98.1]
Feb 18 12:31:07 ts7600-47aad3 pppd[3242]: Connection terminated.
Feb 18 12:31:07 ts7600-47aad3 pppd[3242]: Modem hangup
Feb 18 12:31:07 ts7600-47aad3 pppd[3242]: Exit.
Feb 18 12:31:07 ts7600-47aad3 wvdial: Disconnecting at Tue Feb 18 12:31:07 2014
Feb 18 12:31:07 ts7600-47aad3 wvdial: The PPP daemon has died: A modem hung up t
he phone (exit code = 16)
Feb 18 12:31:07 ts7600-47aad3 wvdial: man pppd explains pppd error codes in more
 detail.

Answer 1

重要提示：您始终可以使用本地选项覆盖默认选项。

从man pppd

   /etc/ppp/options
          System default options for pppd, read before user default 
          options or command-line options.

并且

~/.ppprc
/etc/ppp/options.ttyname
/etc/ppp/peers

你应该启用调试选项（有时也启用 kdebug）

   debug  Enables connection debugging facilities.  If this option
   is given, pppd will log the contents of all control packets  sent  
   or  received  in a readable form.  The packets are logged 
   through syslog with facility daemon and level debug.  This 
   information can be directed to  a  file  by  setting  
   up  /etc/syslog.conf  appropriately  (see  sys-log.conf(5)).

您的退出代码

   EXIT STATUS
      16     The link was terminated by the modem hanging up.

等等。

您的错误是LCP terminated by peer 有几个链接解释了如何修复它：

you'll need to pass "refuse-eap" option to pppd. 乌班图

lcp_term_authentication

或者只是检查您的凭据。