路由器故障判断及排除(7)

现象:MODEM不拨号.

建议:MODEM不拨号,排除掉硬件,线缆的可能,就是:

1. 不感兴趣的包.用show running-config检查路由器配置,是否设置了dialer-list截段了你想传送的包,若是请重新配置access-list表.

2. Chat script配置错误.打开debug信息.

Router#debug dialer

%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to down %LINK-3-UPDOWN: Interface Serial0, changed state to down

%LINK-3-UPDOWN: Interface Async1, changed state to down

Async1: re-enable timeout

Async1: sending broadcast to default destination get_free_dialer: faking it Async1: Dialing cause: Async1: ip PERMIT

Async1:No holdq created - not configured

Async1: Attempting to dial 8292

CHAT1: Attempting async line dialer script

CHAT1: Dialing using Modem script: backup & System script: none -- failed, not connected

CHAT1: process started

CHAT1: Asserting DTR

CHAT1: Chat script backup started

CHAT1: Expecting string:

Async1: sending broadcast to default destination -- failed, not connected CHAT1: Timeout expecting:

CHAT1: Chat script backup finished, status = Connection timed out; remote host not responding

Async1: disconnecting call

......

帧中继连接的Troubleshooting

1. 用show interface serial查看interface和line protocol是否up.确定连接的线缆正确.

2. 如果interface is up,但line protocol是down.用show frame-relay lmi查看帧中继的LMI类型.

3. 用show frame-relay map查看打包类型.

4. 用show frame-relay pvc查看PVC.

5. 打开debug信息.