📄 troubleshooting.htm
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</font>d.MODEM之间没通,即专线没通.<br>
解决办法:作测试环路.请电信局帮助确定具体出现问题是哪一段线路.若作环路成功,line
protocol会变成up(looped).<br>
</li>
<li>若Serial is up,但line protocol is up(looped).<br>
用<em><strong>show running-config</strong></em>看看端口是否作了loopback配置,若有删调它.<br>
MODEM是否作了环路测试.<br>
专线是否作了环路测试.<br>
</li>
<li>若Serial is admsinstratively down,line protocol is down.<br>
<font size="2">Router#conf t<br>
Router(config)#interface serial 0<br>
Router(config-if)#<strong>no shutdown</strong><br>
Router(config-if)#^Z<br>
Router#</font></li>
</ol>
<hr>
<p><a name="ee4"></a><font color="#008080" size="4"><em><strong>电话拨号连接的Troubleshooting</strong></em></font></p>
<p>要解决用电话拨号网连接出现的问题,首先要:</p>
<blockquote>
<p>确定路由器与MODEM之间已连接</p>
</blockquote>
<blockquote>
<p>明白<em><strong>show line</strong></em>输出的含义</p>
</blockquote>
<p><font color="#808080"><em><strong>确定路由器与MODEM之间已连接</strong></em></font></p>
<p>我们在路由器上用反Telnet(Reverse Telnet Session)到MODEM,来确定路由器与MODEM之间的连接.也就是说,反向登录到MODEM上面可对它用AT指令作配置.具体步骤如下:</p>
<ol>
<li>在路由器控制台上,用命令<br>
<strong>telnet</strong><em> ip-address </em><strong>20</strong><em>yy<br>
</em>其中 <em>ip-address</em>
是一个活动端口的地址,<em> yy</em> 是连接MODEM的line线.例如,下面例子是用IP地址192.169.53.52连接到辅助口上:<br>
<strong>telnet 192.169.53.52 2001<br>
</strong></li>
<li>如果连接被拒绝,可能有其它用户连接在该口上.用<strong>show
users</strong> EXEC命令决定是否被占用,若是,<strong>clear
line</strong>清除它;若没有,重试反Telnet.<br>
</li>
<li>如果连接仍被拒绝,确认MODEM控制<strong>modem
inout</strong>.<br>
</li>
<li>确定路由器txspeed和rxspeed与MODEM设置的数率一致.<br>
</li>
<li>反Telnet登录成功后,<strong>AT</strong>命令确定应答OK.</li>
</ol>
<p><font color="#808080"><em><strong>明白show line输出的含义</strong></em></font></p>
<p><strong>Show line </strong><em>line-number</em> EXEC是非常有用的trobbleshooting命令.</p>
<p><img src="gif/s3309.gif" width="599" height="359"></p>
<p>现象:<font color="#808080"><em><strong>MODEM和路由器间无连接.试用反登录无反应或用户收到"Connection
Refused by Foreign Host"信息.</strong></em></font></p>
<p>建议:</p>
<ol>
<li>用<strong>show line</strong>看MODEM一栏是否是"inout",若不是,在路由器上:<br>
<font size="2">Router#conf t<br>
Router(config)#line aux 0<br>
Router(config-line)#<strong>modem inout</strong><br>
Router(config-line)#^Z<br>
Router#<br>
</font></li>
<li>确定正确的线缆.<br>
</li>
<li>硬件问题,请与你的代理联系.</li>
</ol>
<p>现象:<font color="#808080"><em><strong>MODEM不拨号.</strong></em></font></p>
<p>建议:MODEM不拨号,排除掉硬件,线缆的可能,就是:</p>
<ol>
<li>不感兴趣的包.用<strong>show running-config</strong>检查路由器配置,是否设置了<strong>dialer-list</strong>截段了你想传送的包,若是请重新配置<strong>access-list</strong>表.<br>
</li>
<li>Chat script配置错误.打开<em><strong>debug</strong></em>信息.<br>
<font size="2">Router#debug dialer<br>
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0,
changed state to down<br>
%LINK-3-UPDOWN: Interface Serial0, changed state to down<br>
%LINK-3-UPDOWN: Interface Async1, changed state to down<br>
Async1: re-enable timeout<br>
Async1: sending broadcast to default destination
get_free_dialer: faking it<br>
Async1: Dialing cause: Async1: ip PERMIT<br>
Async1:No holdq created - not configured<br>
Async1: Attempting to dial 8292<br>
CHAT1: Attempting async line dialer script<br>
CHAT1: Dialing using Modem script: backup & System
script: none -- failed, not connected<br>
CHAT1: process started<br>
CHAT1: Asserting DTR<br>
CHAT1: Chat script backup started<br>
CHAT1: Expecting string:<br>
Async1: sending broadcast to default destination --
failed, not connected<br>
CHAT1: Timeout expecting:<br>
CHAT1: Chat script backup finished, status = Connection
timed out; remote host not responding<br>
Async1: disconnecting call<br>
......</font></li>
</ol>
<hr>
<p><a name="ee5"></a><font color="#008080" size="4"><em><strong>帧中继连接的Troubleshooting</strong></em></font></p>
<ol>
<li>用<em><strong>show interface serial</strong></em>查看interface和line
protocol是否up.确定连接的线缆正确.<br>
</li>
<li>如果interface is up,但line protocol是down.用<strong>show
frame-relay lmi</strong>查看帧中继的LMI类型.<br>
</li>
<li>用<strong>show frame-relay map</strong>查看打包类型.<br>
</li>
<li>用<strong>show frame-relay pvc</strong>查看PVC.<br>
</li>
<li>打开<strong>debug</strong>信息.</li>
</ol>
<hr>
<p><a name="ee6"></a><font color="#008080" size="4"><em><strong>X.25连接的Troubleshooting</strong></em></font></p>
<ol>
<li>确定两个X.25端口连接上.<br>
MODEM状态:若线路已连通,MODEM的CD灯和RD灯应该亮,表示X.25交换机有数据发送过来.<br>
我们也可以用<em><strong>pad</strong></em>
本地或对方的X.121地址,若能pad过去,说明行X.25网链路层已通.<br>
Router#pad 28050103(对方的X.121地址)<br>
</li>
<li>用<em><strong>show interface serial</strong></em>命令.若serial
is down,line protocol is down请检查路由器与MODEM连接线缆,换另外串口重试.<br>
</li>
<li>若serial is up,但line protocol is down.请与电信局联系,检查LAPB参数是否匹配.<br>
</li>
<li>若serial is up,line protocol is up.但ping对方广域网口不通.<br>
用<strong>show running-config</strong>查看串口是否作了<strong>x25
map ip</strong>设置.<br>
X.25设置中,最大虚电路数值是否超过了申请的值.<br>
</li>
<li><pre><font size="4" face="宋体">若对方连接的不是路由器,而是一块X.25网卡(以博达卡为例)
环境:
知识:博达X.25卡上
#cd /etc/x.25
#vi x25.profile (网卡参数设定文件)
LOCADDR 28050103 (本地X.25端口X.121地址)
VC 16
IVC 0 (呼入VC数)
OVC 0 (呼出VC数)
PVC 0 (永久VC数)
X25TIMEOUT 60 (拆链时间)
故,SVC=VC-IVC-OVC-PVC.
#x25reset (重启X.25网卡)
#x25link (监控当前状态信息)
#vi x25.addr (地址对应文件,IP层能互相通信,要把X.121地址与IP地址对应起来)
130.132.128.4 28050104 SVC 0
130.132.128.3 28050103 SVC 0
#cd /etc
#vi tcp 加上
ifconfig x25 130.132.128.3 -arp network 255.255.0.0
</font><img src="gif/WarningA034.gif" width="28" height="28"><font
size="4" face="宋体">一般X.25连接出现问题都是一方的IP地址与X.121地址之间映射没有设定.</font></pre>
</li>
</ol>
<hr>
<p><a name="ee7"></a><font color="#008080" size="4"><em><strong>与IBM主机连接的Troubleshooting</strong></em></font></p>
<ul>
<li><a href="#ee8"><font color="#008080">DLSw+
Troubleshooting</font></a></li>
<li><a href="#ee9"><font color="#008080">STUN Troubleshooting</font></a></li>
<li><a href="#ee10"><font color="#008080">CIP Troubleshooting</font></a></li>
</ul>
<p><a name="ee8"></a><font color="#808080"><em><strong>DLSw+
Troubleshooting</strong></em></font></p>
<p>在用DLSw+通过路由器实现PU2.0/2.1与IBM大型主机之间连接,我们要同时用<em><strong>show
dlsw</strong></em>和<em><strong>show interface serial</strong></em>命令解决出现的问题.</p>
<ol>
<li><pre><font size="4" face="宋体">首先检查DLSw+定义的两个<tt>对等</tt>peers是否连通</font>
<font size="3" face="宋体">Router#<em><strong>show dlsw peers</strong></em>
Peers: state pkts-rx pkts-tx type drops ckts TCP uptime
TCP <strong>17.18.15.1</strong> <strong>CONNECT</strong> 16080 8400 conf 0 0 0 00.03.27
TCP <strong>1.1.12.1</strong> <strong> DISCONN</strong> 0 0 conf 0 0 0 00.00.00</font></pre>
<pre><font size="4" face="宋体"><em><tt>Peers</tt></em><tt> --- 对应"dlsw remote-peer"定义的对等peers IP地址.
</tt><em><tt>state</tt></em><tt> --- 表示与对等peers的连接状态.
其中:</tt></font><font color="#008000" size="4" face="宋体"><tt>CONNECT</tt></font><font
size="4" face="宋体"><tt>表示对等peers已建立.
</tt></font><font color="#000080" size="4" face="宋体"><tt>CAP_EXG</tt></font><font
size="4" face="宋体"><tt>表示与远程peer交换性能信息.
</tt></font><font color="#008080" size="4" face="宋体"><tt>WAIT_RD</tt></font><font
size="4" face="宋体"><tt>是建立peer连接的最后一步,等待远程peer应答信息.
</tt></font><font color="#FF0000" size="4" face="宋体"><tt>DISCONN</tt></font><font
size="4" face="宋体"><tt>表示与对等peers没有建立连接,请参阅TCP/IP Troubleshooting检查TCP连接故障.
</tt></font><font color="#00FFFF" size="4" face="宋体"><tt>WAN_BUSY</tt></font><font
size="4" face="宋体"><tt>表示TCP传输队列已满,不能传输数据.</tt></font></pre>
</li>
<li><font size="4" face="宋体"><tt>若对等peers已建立连接,请查看性能交换信息.<br>
Router#</tt><em><strong><tt>show dlsw capabilities</tt></strong></em><tt><br>
</tt></font><font size="4" face="Times New Roman"><tt>DLSw:
Capabilities for peer </tt><strong><tt>172.18.15.166</tt></strong><tt><br>
vendor id (OUI) : '00C' (cisco)<br>
version number : 1<br>
release number : 0<br>
init pacing window : 20<br>
unsupported saps : none<br>
num of tcp sessions :1<br>
loop prevent support : no<br>
icanreach mac-exclusive : no<br>
icanreach netbios-excl. : no<br>
reachable mac addresses : none<br>
reachable netbios names : none<br>
cisco version number : 1<br>
peer group number :</tt><strong><tt> 0</tt></strong><tt><br>
border peer capable : </tt><strong><tt>no</tt></strong><tt><br>
peer cost :</tt><strong><tt> 3</tt></strong><tt><br>
biu-segment configured : no<br>
local-ack configured: </tt><strong><tt>yes</tt></strong><tt><br>
priority configured: no<br>
version string :<br>
Cisco Internetwork Operating System Software<br>
IOS (tm) GS Software (GS7-K-M), Experimental Version
11.1(10956) [sbales 139]<br>
Copyright (c) 1986-1996 by cisco Systems, Inc.<br>
Compiled Thu 30-May-96 09:12 by sbales8</tt></font><br>
</li>
<li><pre><font size="4" face="宋体">交换过性能信息后,就要寻找目的MAC地址了,显示出所有的路由器能够到达的MAC地址(本地和远端)
</font><font size="3" face="宋体">Router#<em><strong>show dlsw reachability</strong></em>
</font><font size="3">DLSw MAC address reachability cache list
Mac Addr status Loc. peer/port rif
0000.810f.6500 FOUND LOCAL TBridge-001 --no rif--
0006.e918.7b70 FOUND LOCAL TBridge-001 --no rif--
1000.5ae3.03f7 FOUND LOCAL TBridge-001 --no rif--
7500.9221.0000 FOUND REMOTE 16.201.30.250(2065) max-lf(4472)
7500.9221.0000 SEARCHING LOCAL
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