前段时间写那个adsl拨号脚本的时候修改了/etc/sysconfig/network-scripts/ifcfg-cnc，结果就出现问题了，具体可查看这篇文章。当时按照前面文章的修改后已经有好长一段时间拨号都正常，但是今天早上拨号的时候突然发现又出现问题了，而且情况似乎与前一次差不多，以下是拨号的日志：
May 18 09:26:04 cocobear pppd[1630]: pppd 2.4.3 started by root, uid 0
May 18 09:26:04 cocobear pppd[1630]: Using interface ppp0
May 18 09:26:04 cocobear pppd[1630]: Connect: ppp0 < --> /dev/pts/0
May 18 09:26:04 cocobear pppoe[1642]: PADS: Service-Name: ''
May 18 09:26:04 cocobear pppoe[1642]: PPP session is 9283
May 18 09:26:05 cocobear pppd[1630]: CHAP authentication succeeded: Welcome to .May 18 09:26:05 cocobear pppd[1630]: local IP address 124.89.60.31
May 18 09:26:05 cocobear pppd[1630]: remote IP address 221.11.2.1
May 18 09:26:05 cocobear pppd[1630]: primary DNS address 221.11.1.67
May 18 09:26:05 cocobear pppd[1630]: secondary DNS address 221.11.1.68
May 18 09:36:10 cocobear pppd[1630]: No response to 3 echo-requests
May 18 09:36:10 cocobear pppd[1630]: Serial link appears to be disconnected.
May 18 09:36:10 cocobear pppd[1630]: Connect time 10.1 minutes.
May 18 09:36:10 cocobear pppd[1630]: Sent 490999 bytes, received 5168828 bytes.
May 18 09:36:16 cocobear pppd[1630]: Connection terminated.
May 18 09:36:16 cocobear pppd[1630]: Modem hangup
May 18 09:36:21 cocobear pppd[1630]: Exit.
May 18 09:36:21 cocobear pppoe[1642]: read (asyncReadFromPPP): Session 9283: Input/output error
May 18 09:36:21 cocobear pppoe[1642]: Sent PADT
May 18 09:36:21 cocobear adsl-connect: ADSL connection lost; attempting re-conne
刚拨号成功连线10分钟就断开，通过Google搜索“No response to 3 echo-requests“，也没有什么比较有用的介绍，只有一篇文章中提到要修改/etc/ppp/options中的lcp-echo-failure值，把它改的大一点，但我的Fedora core 5的这个文件没有那一选项，不过我倒是在同一目录中的pppoe-server-options文件中找到那个选项，可惜的是修改后问题仍然存在。
May 18 09:36:27 cocobear pppd[2038]: pppd 2.4.3 started by root, uid 0
May 18 09:36:27 cocobear pppd[2038]: Using interface ppp0
May 18 09:36:27 cocobear pppd[2038]: Connect: ppp0 < --> /dev/pts/0
May 18 09:36:58 cocobear pppd[2038]: LCP: timeout sending Config-Requests
May 18 09:36:58 cocobear pppd[2038]: Connection terminated.
May 18 09:36:58 cocobear pppd[2038]: Using interface ppp0
May 18 09:36:58 cocobear pppd[2038]: Connect: ppp0 < --> /dev/pts/4
May 18 09:37:02 cocobear pppoe[2039]: Timeout waiting for PADO packets
May 18 09:37:03 cocobear pppd[2038]: tcflush failed: Bad file descriptor
May 18 09:37:03 cocobear pppd[2038]: Exit.
后来重拨时一直是上面的错误， “LCP: timeout sending Config-Requests”，在Google搜索了很多关于这个错误的页面，但也没有找到比较有用的信息。
May 18 10:30:52 cocobear pppd[2674]: pppd 2.4.3 started by root, uid 0
May 18 10:30:52 cocobear pppd[2674]: Using interface ppp0
May 18 10:30:52 cocobear pppd[2674]: Connect: ppp0 < --> /dev/pts/8
May 18 10:31:06 cocobear pppoe[2675]: PADS: Service-Name: ''
May 18 10:31:06 cocobear pppoe[2675]: PPP session is 11436
May 18 10:31:06 cocobear pppd[2674]: CHAP authentication succeeded: Welcome to .May 18 10:31:06 cocobear pppd[2674]: local IP address 124.89.79.5
May 18 10:31:06 cocobear pppd[2674]: remote IP address 221.11.2.1
May 18 10:31:06 cocobear pppd[2674]: primary DNS address 221.11.1.67
May 18 10:31:06 cocobear pppd[2674]: secondary DNS address 221.11.1.68
May 18 10:32:26 cocobear pppd[2674]: No response to 3 echo-requests
May 18 10:32:26 cocobear pppd[2674]: Serial link appears to be disconnected.
May 18 10:32:26 cocobear pppd[2674]: Connect time 1.4 minutes.
May 18 10:32:26 cocobear pppd[2674]: Sent 1946 bytes, received 1038 bytes.
May 18 10:32:26 cocobear pppoe[2648]: Timeout waiting for PADO packets
May 18 10:32:32 cocobear pppd[2674]: Connection terminated.
May 18 10:32:32 cocobear pppd[2674]: Modem hangup
May 18 10:32:37 cocobear pppd[2674]: Exit.
May 18 10:32:37 cocobear pppoe[2675]: read (asyncReadFromPPP): Session 11436: Input/output error
May 18 10:32:37 cocobear pppoe[2675]: Sent PADT
May 18 10:32:37 cocobear adsl-connect: ADSL connection lost; attempting re-connection.
这个是重试了N次后终于连线上去，但只有1.4分钟的时间，又是”No response to 3 echo-requests“这个错误。
最后在一篇文章中看到重新使用adsl-setup创建一个ppp拨号。照着做了后结果竟然可以连接上去，而且好长时间也再没有断开！
USERCTL=yes
BOOTPROTO=dialup
NAME=DSLppp0
DEVICE=ppp0
TYPE=xDSL
ONBOOT=no
PIDFILE=/var/run/pppoe-adsl.pid
FIREWALL=NONE
PING=.
PPPOE_TIMEOUT=80
LCP_FAILURE=3
LCP_INTERVAL=20
CLAMPMSS=1412
CONNECT_POLL=6
CONNECT_TIMEOUT=60
DEFROUTE=yes
SYNCHRONOUS=no
ETH=eth0
PROVIDER=cnc
USER=11100022395
PEERDNS=no
DEMAND=no
IPV6INIT=no
PERSIST=no
这是新产生的ifcfg-ppp0的文件内容。
直到现在还是没有弄明白这到底是怎么一回事，写在这里只做个记录吧，如果有人知道原因告诉我一声就更好了。
似乎还有人提到这可能和ISP有关，这个原理我倒是觉得很有可能，我们学校Windows下有时候拨号也是老拨不上去，但具体的错误和这个是否一样，我就不得而知了。
Comments
cocobear: TO:wangcong 这个和咱们那个脚本没有关系啊，那个脚本没把改变/etc/sysconfig/network-scripts/ifcfg-XXX里的选项，只是改变用户名的 有两个USER应该是运行脚本非正常退出产生的吧？
wangcong: 我早就遇到这个问题了。貌似是咱那脚本有问题，在我这里运行完，那个配置文件中有两个USER=XXXXX。 而且，我发现，那两个timeout也不能随便改。
