Cisco网络故障的基本排除方法
Cisco网络故障的基本排除方法
  1.故障判断及排除(Troubleshooting)
  这里我们介绍在使用路由器时可能出现的硬件,软件问题;在联网过程中,X.25,FR, DDN,DDR, TCP/IP,IBM大型主机互连等不同网络环境碰到的问题及解决办法. · Troubleshooting的工具 · TCP/IP连接的Troubleshooting · 串口连接遇到问题的Troubleshooting · 电话拨号连接的Troubleshooting · 帧中继连接的Troubleshooting · X.25连接的Troubleshooting · IBM主机连接的Troubleshooting
 
  2.Troubleshooting的工具
  Troubleshooting的工具有许多种,可以用路由器的诊断命令,Cisco网络管理工具(CiscoWorks)和规程分析仪等等方法.下面我们主要介绍路由器的诊断命令.
  路由器诊断命令有四种:
  · show 命令
  · debug 命令
  · ping 命令
  · trace 命令
  用 show 命令
  Show是一个很有用的监控命令和解决系统出现问题的工具.下面是几个通常用到的show命令:
  · show interface---显示接口统计信息.
 
  一些常用的show interface命令:
  · show interface ethernet
  · show interface tokenring
  · show interface serial
  · show controllers---显示接口卡控制器统计信息.
 
  一些常用的show controllers命令:
  · show controllers cxbus
  · show controllers e1
  · show running-config---显示当前路由器正在运行的配置.
  · show startup-config---显示存在NVRAM配置.
  · show flash---Flash memory内容.
  · show buffers---显示路由器中bufferpools统计信息.
  · show memory---路由器使用内存情况的统计信息,包括空闲池统计信息.
  · show processes---路由器活动进程信息.
  · show version---显示系统硬件,软件版本,配置文件和启动的系统映象.
  用 debug 命令
  在超级用户模式下的debug命令能够提供端口传输信息,节点产生的错误消息,诊断协议包和其它有用的troubleshooting数据.
  !! 注意:使用debug命令要注意,它会占用系统资源,引起一些不可预测现象.终止使用debug命令请用nodebug all命令.
  Debug命令默认是显示在控制台端口上的,可用logbuffer命令把输出定向到buffers里面.若是telnet过去的,可用Router#terminalmonitor监控到控制台信息.
  用ping命令
  Ping确定网络连通.
  用 trace 命令
  Trace命令跟踪路由器包传输.
  3.TCP/IP连接的Troubleshooting
  现象:主机到本地路由器的以太口不通
  建议:我们可以把路由器的以太网口看作是普通主机的以太网卡,这就成了一个局域网连接问题,
  1. show interface ethernet number命令
  Router#show interface ethernet 0
  Ethernet is up,line protocol is down
  2. Ethernet is down,请把线缆(同轴线缆或双绞线)接上.若已接上,ethernet依然是down,请你的代理联系.
  3. Ethernet is admsinstratively down.
  Router#conf t
  Router(config)#interface ethernet 0
  Router(config-if)#no shutdown
  Router(config-if)#^Z
  Router#
  4. Ethernet is up,line protocol is down.
  主机10M网卡接到路由器100M的以太口上面,它不是自适应的(目前版本).反之无问题.
  若是同轴线缆请检查线缆,T型头,终结器,是否连接正确.
  若是双绞线请检查线缆是否正确,中间是否通过HUB连接,若是直连主机要用交叉线.
  若是100BaseTX接口,需要用五类双绞线.
  若是一个接口提供两种物理介质,如粗缆AUIUTPRJ45,默认为AUI.要用RJ45需要:
  Router#conf t
  Router(config)#interface ethernet 0
  Router(config-if)#media-type 10baset
  Router(config-if)#^Z
  Router#
  5. Ethernet is up,line protocol is up;ping不通.
  请查看路由器以太口的IP地址,是否与主机IP地址在同一个网段上.
  6. 经过以上几个步骤,问题仍未解决,请你的代理联系.
  现象:主机到对方路由器广域网口或以太网口不通.
  建议:假设主机到本地路由器的以太口已通.
  1. 在路由器上检查两个广域网口之间是否通,若不通,请看下面关于广域网的troubleshooting.
  2. 若路由器两个广域网口之间是通的.
  在主机上用"netstat -rn"命令查路由,若没有请用"routeadd"加入.
  以SCO UNIX为例:
  #netstat -rn
  #route add 目的网段 掩码 网关 1
  或
  #vi /etc/gateways
  net 目的网段 gateway 本地路由器以太口地址metric 1 passive
  3. 若主机上有默认网关,检查路由器路由协议配置.
  Router#show ip route
  Router#show running-config
  .
  .
  .
  router eigrp 1
  network ...
  network ...
  两端路由器配置路由协议是否一致,是否在一个自治系统里面."network"加入的网段是否正确.
  现象:主机到对方目的主机不通.
  建议:按以下步骤解决.
  1. 检查主机到本地路由器的以太口.
  2. 检查两个广域网口.
  3. 检查主机到对方路由器广域网口.
  4. 检查主机到对方路由器以太网口.
  可用telnet命令远程登录到对方路由器上,按检查本地主机到本地路由器的以太口的方法检查对方局域网连接情况.
  5. 重复34,检查对方到本地情况.
  6. 经过以上几个步骤,问题仍未解决,请你的代理联系.
  4.串口连接遇到问题的Troubleshooting
  现象:在专线连接时,路由器直连的两个广域网口间不通.
  建议:我们可以把两个路由器广域网口之间分成三段,如图所示:
  路由器A--1---MODEMA----2----MODEMB--3--路由器B
  我们的任务就是要检查出是哪一段不通并解决它.
  1. show interface serial number命令
 
  2. 若是Serial is down,表示路由器到本地的MODEM之间无载波信号CD.
  连接串口和MODEM,开启MODEM.MODEM的发送灯TD是否亮,TD灯亮表示路由器有信号发送给MODEM.TD灯若不亮,请检查MODEM,线缆(最好用Cisco所配的)和端口.你可以用另外一个串口再试试看.
  3. Serial is up,line protocol is down.有几种可能:
  a.本地路由器未作配置.
  b.远端路由器未开或未配置.
  路由器两端需要配置相同的协议打包方式.例如:路由器A打包HDLC,路由器B打包PPP,那么两台路由器的lineprotocol始终是down.改变打包方式:
  Router#conf t
  Router(config)#interface serial 0
  Router(config-if)#encapsulation ppp
  Router(config-if)#^Z
  Router#
  c.若是使用Newbridge26XX,27XXDTU设备,它不发送CD信号,请在路由器上设置:
  Router#configure terminal
  Router(config)#int serial 0
  Router(config-if)#ignored-dcd
  Router(config-if)#^Z
  Router#
  d.MODEM之间没通,即专线没通.
  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,lineprotocol会变成up(looped).
  4. Serial is up,line protocol is up(looped).
  用show running-config看看端口是否作了loopback配置,若有删调它.
  MODEM是否作了环路测试.
  专线是否作了环路测试.
  5. Serial is admsinstratively down,line protocol is down.
  Router#conf t
  Router(config)#interface serial 0
  Router(config-if)#no shutdown
  Router(config-if)#^Z
  Router#
  5.电话拨号连接的Troubleshooting
  要解决用电话拨号网连接出现的问题,首先要:
  确定路由器与MODEM之间已连接
  明白show line输出的含义
  确定路由器与MODEM之间已连接
  我们在路由器上用反Telnet(Reverse Telnet Session)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:
  1. 在路由器控制台上,用命令
  telnet ip-address 20yy
  其中 ip-address是一个活动端口的地址, yy 是连接MODEMline线.例如,下面例子是用IP地址192.169.53.52连接到辅助口上:
  telnet 192.169.53.52 2001
  2. 如果连接被拒绝,可能有其它用户连接在该口上.showusers EXEC命令决定是否被占用,若是,clearline清除它;若没有,重试反Telnet.
  3. 如果连接仍被拒绝,确认MODEM控制modeminout.
  4. 确定路由器txspeedrxspeedMODEM设置的数率一致.
  5. Telnet登录成功后,AT命令确定应答OK.
  明白show line输出的含义
  Show line line-number EXEC是非常有用的trobbleshooting命令.
 
  现象:MODEM和路由器间无连接.试用反登录无反应或用户收到"ConnectionRefused by Foreign Host"信息.
  建议:
  1. show lineMODEM一栏是否是"inout",若不是,在路由器上:
  Router#conf t
  Router(config)#line aux 0
  Router(config-line)#modem inout
  Router(config-line)#^Z
  Router#
  2. 确定正确的线缆.
  3. 硬件问题,请与你的代理联系.
  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.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.
  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 destinationget_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 & Systemscript: 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 = Connectiontimed out; remote host not responding
  Async1: disconnecting call
  ......
  6.帧中继连接的Troubleshooting
  1. show interface serial查看interfacelineprotocol是否up.确定连接的线缆正确.
  2. 如果interface is up,line protocoldown.showframe-relay lmi查看帧中继的LMI类型.
  3. show frame-relay map查看打包类型.
  4. show frame-relay pvc查看PVC.
  5. 打开debug信息.
  7.X.25连接的Troubleshooting
  确定两个X.25端口连接上.
  MODEM状态:若线路已连通,MODEMCD灯和RD灯应该亮,表示X.25交换机有数据发送过来.
  我们也可以用pad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.
  Router#pad 28050103(对方的X.121地址)
 
  用show interface serial命令.serialis down,line protocol is down请检查路由器与MODEM连接线缆,换另外串口重试.
 
  若serial is up,line protocol is down.请与电信局联系,检查LAPB参数是否匹配.
 
  若serial is up,line protocol is up.ping对方广域网口不通.
  用show running-config查看串口是否作了x25map ip设置.
  X.25设置中,最大虚电路数值是否超过了申请的值.
 
  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) OVC 0 (呼出VC) PVC 0 (永久VC) X25TIMEOUT 60 (拆链时间),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.
 
  8.IBM主机连接的Troubleshooting
 
  DLSw+Troubleshooting
  STUN Troubleshooting
  CIP Troubleshooting
  DLSw+Troubleshooting
 
  在用DLSw+通过路由器实现PU2.0/2.1IBM大型主机之间连接,我们要同时用showdlswshow interface serial命令解决出现的问题.
 
  首先检查DLSw+定义的两个对等peers是否连通Router#show dlsw peersPeers: state pkts-rx pkts-tx type drops ckts TCP uptime TCP 17.18.15.1 CONNECT 16080 8400 conf 0 0 0 00.03.27 TCP 1.1.12.1 DISCONN 0 0 conf 0 0 0 00.00.00
  Peers --- 对应"dlsw remote-peer"定义的对等peers IP地址.state --- 表示与对等peers的连接状态.其中:CONNECT表示对等peers已建立. CAP_EXG表示与远程peer交换性能信息. WAIT_RD是建立peer连接的最后一步,等待远程peer应答信息. DISCONN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. WAN_BUSY表示TCP传输队列已满,不能传输数据.
  若对等peers已建立连接,请查看性能交换信息.
  Router#show dlsw capabilities
  DLSw:Capabilities for peer 172.18.15.166
  vendor id (OUI) : 00C (cisco)
  version number : 1
  release number : 0
  init pacing window : 20
  unsupported saps : none
  num of tcp sessions :1
  loop prevent support : no
  icanreach mac-exclusive : no
  icanreach netbios-excl. : no
  reachable mac addresses : none
  reachable netbios names : none
  cisco version number : 1
  peer group number : 0
  border peer capable : no
  peer cost : 3
  biu-segment configured : no
  local-ack configured: yes
  priority configured: no
  version string :
  Cisco Internetwork Operating System Software
  IOS (tm) GS Software (GS7-K-M), Experimental Version11.1(10956) [sbales 139]
  Copyright (c) 1986-1996 by cisco Systems, Inc.
  Compiled Thu 30-May-96 09:12 by sbales8
 
  交换过性能信息后,就要寻目的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)Router#show dlsw reachabilityDLSw MAC address reachability cache listMac Addr status Loc. peer/port rif0000.810f.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 LOCALDLSw NetBIOS Name reachability cache listNetBIOS Name status Loc. peer/port rifSXUSER2 FOUND LOCAL TBridge-001 --no rif--
  若本地MAC地址和目的MAC地址状态均是FOUND,请参看第五步.
  SEARCHING表示在寻本地MAC地址或目的MAC地址.此时用show interface serial命令查看该口连接的PU状态.
  NOT_FOUND表示没有收到对PU轮询的应答.
  VERIFY表示确认缓存内信息.
 
  在SERACHING本地MAC地址或目的MAC地址.Router#show interface serial 0Serial1 is up, line protocol is up Hardware is HD64570 MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation SDLC, loopback not set Router link station role: SECONDARY (DTE) Router link station metrics: group poll not enabled poll-wait 40000 seconds N1 (max frame size) 12016 bits modulo 8 sdlc vmac: 4000.5555.00-- sdlc addr C1 state is DISCONNECT cls_state is CLS_STN_CLOSED VS 0, VR 0, Remote VR 0, Current retransmit count 0 Hold queue: 0/200 IFRAMEs 0/0 TESTs 0/0 XIDs 0/0, DMs 0/0 FRMRs 0/0 RNRs 0/0 SNRMs 0/0 DISC/RDs 0/0 REJs 0/0 chain: C1/C1 Last input never, output never, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 0 packets output, 0 bytes, 0 underruns 0 output errors, 0 collisions, 19 interface resets 0 output buffer failures, 0 output buffers swapped out 6 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=up说明:Encapsulation SDLC---串口打包方式为SDLC.Router link station role: SECONDARY (DTE)---目前端口作secondary,"sdlc role"命令设置.sdlc vmac: 4000.5555.00-- ---"sdlc vmac"设置的MAC地址.注意它的最后两位是留给PU地址的. 在本例中,端口MAC地址是4000.5555.00C1.sdlc addr C1 state is DISCONNECT ---该端口连接PU C1当前状态.有以下几种状态: DISCONNECT -PU未连接,次站没有发TESTXID帧请求建立连接.请检查下面连接的PU是否启动 SNA进程,若是用DCE线缆连接PU请检查线缆是否正确,若是MODEM连接到远端PU, 检查MODEM状态灯. DISCSENT-路由器发送断开请求(DISC)给次站,正在等待次站应答. SNRMSENT-路由器发送连接请求(SNRM)给次站,正在等待次站应答.这个状态出现在作主站的路由器 .若是在作主站路由器上出现SNRMSENT状态,检查下端PU是否开机,路由器端口与PU SDLC口连接的MODEM是否已通(MODEMDTR,CD,RXD,TXD灯应常亮).一句话,出现SNRMSENT 状态是路由器端口与它下端PU之间问题. CONNECT-PU连接正常.路由器和它连接的次站正常连接. THEMBUSY-PU发送RNR.次站告诉路由器暂时不能接收任何信息. USBUSY-路由器发送RNR.路由器告诉次站暂时不能接收任何信息.路由器已接收到次站对SNRM帧的 应答帧UA,试图建立SDLCLLC2会话. BOTHBUSY-双方均发送RNR.告诉对方暂时不能接收任何信息. ERROR-违反SDLC协议.路由器正在等待次站应答. SNRMSEEN-路由器作次站,接收到SNRM.
  当双方MAC地址都到后,开始建立链路了.Router#show dlsw curcuitIndex local addr(lsap) remote addr(dsap) state1818740 1000.5ae3.430d(04) 4000.5555.00c1(04) CONNECTED"show interface serial"查看PU状态应是"CONNECT".
  我们也可以用"debug dlsw"获得更多的信息帮助解决网络中出现的问题.你可以记录下debug传输信息提供给你的代理.
 
  问题:远端没有到达本端机器.远端peerIP地址是172.18.16.156.
 
  建议:
  检查show dlsw peer输出,我们看到:Peers: state pkts-rx pkts-tx type drops ckts TCP uptime TCP 172.18.16.156 DISCONN 0 0 conf 0 0 0 --
  用debug dlsw peers命令决定问题:
  DLSw:action_a() attempting to connect peer 172.18.15.156(2065)
  DLSw:action_a(): Write pipe opened for peer172.18.15.156(2065)
  DLSw:peer 172.18.15.156(2065), old state DISCONN, new stateWAIT_RD
  DLSw:dlsw_tcpd_fini() for peer 172.18.15.156(2065)
  DLSw:tcp fini closing connection for peer 172.18.15.156(2065)
  DLSw:action_d(): for peer 172.18.15.156(2065)
  DLSw:peer 172.18.15.156(2065), old state WAIT_RD, new stateDISCONN
  DLSw:Not promiscuous - Rej conn from 172.18.15.166(2065)
  诊断:试着打开peer172.18.15.156,但不成功.DLSw+接收到来自172.18.15.166的打开请求,但是DLSw+拒绝它,因为这个peer没有定义.由此我们可以判断定义peer地址不正确.peer地址为172.18.15.166就连通了.
 
  Peers: state pkts-rx pkts-tx type drops ckts TCP uptime TCP 172.18.16.166 CONNECT 2 2 conf 0 0 0 00:224:27
  问题:SDLC设备不能连接到主机.Milan是连接SDLC设备的远端peer.
 
  建议:
 
  用show dlsw peer命令显示peerup.milan#sh dlsw peersPeers: state pkts-rx pkts-tx type drops ckts TCP uptime TCP 172.18.16.166 CONNECT 2 2 conf 0 0 0 00:224:27
  Show dlsw circuits没有链路产生.milan#show dlsw circuitsmilan#
  Show interface 命令显示SDLC 地址状态是USBUSY,这表示我们已经成功的连接到下端路由器上.Router#show interface serial 3/7Serial1 is up, line protocol is up Hardware is HD64570 MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation SDLC, loopback not set Router link station role: SECONDARY (DTE) Router link station metrics: group poll not enabled poll-wait 40000 seconds N1 (max frame size) 12016 bits modulo 8 sdlc vmac: 4000.5555.00-- sdlc addr C1 state is USBUSY cls_state is CLS_STN_CLOSED VS 0, VR 0, Remote VR 0, Current retransmit count 0 Hold queue: 0/200 IFRAMEs 0/0 TESTs 0/0 XIDs 0/0, DMs 0/1 FRMRs 20/20 RNRs 620/0 SNRMs 3/0 DISC/RDs 1/0 REJs 0/0 chain: C1/C1 sdlc addr C2 state is USBUSY cls_state is CLS_STN_CLOSED VS 0, VR 0, Remote VR 0, Current retransmit count 0 Hold queue: 0/200 IFRAMEs 0/0 TESTs 0/0 XIDs 0/0, DMs 0/0 FRMRs 0/0 RNRs 730/0 SNRMs 7/0 DISC/RDs 0/0 REJs 0/0 chain: C2/C2 Last input never, output never, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 0 packets output, 0 bytes, 0 underruns 0 output errors, 0 collisions, 19 interface resets 0 output buffer failures, 0 output buffers swapped out 6 carrier transitions DCD=up DSR=up DTR=up RTS=down CTS=up
  检查配置到达的目的MAC地址是4001.3745.1088.milan#write terminal ... ! interface Serial3/7 description sdlc config to MVS mtu 4400 no ip address encapsulation sdlc no keepalive clockrate 9600 sdlc role primary sdlc vmac 4000.1234.5600 sdlc N1 12016 sdlc address C1 sdlc xid C1 05DCCCC1 sdlc partner 4001.3745.1088 C1 sdlc address C2 sdlc xid C2 05DCCCC2 sdlc partner 4001.3745.1088 C2 sdlc dlsw C1 C2 ! ...
  用show dlsw reachability mac-address命令发现MAC地址没到:Router#show dlsw reachability mac-address 4001.3745.1088DLSw MAC address reachability cache listMac Addr status Loc. peer/port rif0000.810f.6500 SEARCHING LOCAL
  在FEP连接的路由器一端,show dlsw reachability mac-address命令发现MAC地址没到:Router#show dlsw reachability mac-address 4001.3745.1088DLSw MAC address reachability cache listMac Addr status Loc. peer/port rif0000.810f.6500 SEARCHING REMOTE
  显示show source-bridge,没有令牌环口走SRB:
  bolzano#showsource-bridge
  Global RSRB Parameters:
  TCP Queue Length maximum: 100
  Ring Group 100:
  No TCP peername set, TCP transport disabled
  Maximum output TCP queue length, per peer: 100
  Rings:
  诊断:加上"source-bridge"命令,连接正常了.
 
  问题:同一个串口上,一个SDLC设备连接正常而其它几个不行.
 
  建议:
 
  用show dlsw peer命令显示peerup.milan#sh dlsw peersPeers: state pkts-rx pkts-tx type drops ckts TCP uptime TCP 172.18.16.166 CONNECT 2 2 conf 0 0 0 00:224:27
  用show dlsw reachability mac-address命令发现MAC地址:Router#show dlsw reachability mac-address 4001.3745.1088DLSw MAC address reachability cache listMac Addr status Loc. peer/port rif0000.810f.6500 FOUND REMOTE 172.18.15.166(2065)
  用show dlsw circuits mac-address命令告诉两个链路连接:milan#show dlsw circuit mac-address 4001.3745.1088 Index local addr(lsap) remote addr(dsap) state 250-00 4000.1234.56c1(04) 4001.3745.1088(04) CONNECTED 251-00 4000.1234.56c2(04) 4001.3745.1088(04) CKT_ESTABLISHED
  用debug dlsw core命令输出:
  milan#debug dlswcore state
  DLSw core statedebugging is on
  milan#
  DLSw: START-FSM(251-00): event:DLC-Id state:CKT_ESTABLISHED
  DLSw: core:dlsw_action_f()
  DLSw: END-FSM(251-00): state:CKT_ESTABLISHED->CKT_ESTABLISHED
  DLSw: START-FSM (251-00): event:DLC-Idstate:CKT_ESTABLISHED
  DLSw: core:dlsw_action_f()
  DLSw: END-FSM(251-00): state:CKT_ESTABLISHED->CKT_ESTABLISHED
  DLSw: START-FSM (251-00): event:WAN-XIDstate:CKT_ESTABLISHED
  DLSw: core:dlsw_action_g()
  DLSw: END-FSM(251-00): state:CKT_ESTABLISHED->CKT_ESTABLISHED
  DLSw: START-FSM (251-00): event:DLC-Idstate:CKT_ESTABLISHED
  DLSw: core:dlsw_action_f()
  DLSw: END-FSM(251-00): state:CKT_ESTABLISHED->CKT_ESTABLISHED
  DLSw: START-FSM (251-00): event:DLC-Idstate:CKT_ESTABLISHED
  DLSw: core:dlsw_action_f()
  DLSw: END-FSM(251-00): state:CKT_ESTABLISHED->CKT_ESTABLISHED
  DLSw: START-FSM (251-00): event:DLC-Idstate:CKT_ESTABLISHED
  DLSw: core:dlsw_action_f()
  DLSw: END-FSM(251-00): state:CKT_ESTABLISHED->CKT_ESTABLISHED
  DLSw: START-FSM (251-00): event:DLC-Idstate:CKT_ESTABLISHED
  DLSw: core:dlsw_action_f()
  DLSw: END-FSM(251-00): state:CKT_ESTABLISHED->CKT_ESTABLISHED
  DLSw: START-FSM (251-00): event:WAN-XIDstate:CKT_ESTABLISHED
  DLSw: core:dlsw_action_g()
  DLSw: END-FSM(251-00): state:CKT_ESTABLISHED->CKT_ESTABLISHED
  DLSw: START-FSM (251-00): event:DLC-Idstate:CKT_ESTABLISHED
  DLSw: core: dlsw_action_f()
  DLSw: END-FSM(251-00): state:CKT_ESTABLISHED->CKT_ESTABLISHED
  诊断:DLSw试图在下端SDLC设备和FEP之间传输XID,FEP并不建立会话.它通常是XID(IDBK/IDNUM)引起的.
  在配置中加上"sdlc xid"后连接正常.
 
  STUNTroubleshooting
 
  确定stun peer连通rick#sh stun peerThis peer: 10.17.5.2 *Serial2 (group 1 [basic]) state rx_pkts tx_pkts dropsall TCP 10.17.5.2 open 5729 5718 0若状态不是open,应是TCP/IP连接问题,请参阅TCP/IP Troubleshooting.
  用show interface确定路由器和主机之间serial isup,line protocol is up.
  若是"down/down"请检查线缆,正确使用DTEDCECable.
  若serial一会儿up,一会儿down,不断反复.你的主机可能配置成半双工的而不是全双工的,使用MSD时路由器没有设成半双工的.
 
  如果serail is up,line protocol is down.最大可能是一端是NRZ编码,另一端是NRZI编码."nrzi-encoding"命令设置NRZI编码.设定编码方式与大机相同.
 
  一旦line操作正常,最常出现的问题就是SDLC地址不对.SDLC地址要与主机PU地址一致.如果收到下面信息就表示SDLC地址与主机PU地址不匹配.
  Received data from wrong address! Expect for outputaddress C2/Got C4.
  Debug sdlc
  当工作正常时,debug输出信息顺序:
  SDLC Primary :
  DISCONNECT-->SDLC PRI WAIT-->NET UP WAIT-->CONNECT
  SDLC Secondary :
  DISCONNECT-->NET UP WAIT-->SDLC SECWAIT-->CONNECT
 
  CIPTroubleshooting
 
  用"show interface channel 3/0"显示物理通道端口状态.channel3/0 is up,line protocol is up.表示物理接口连接正常.否则请检查物理接口,线缆,bypass等是否连接正确.Router#sh int c3/0Channel3/0 is up, line protocol is up Hardware is cyBus Channel Interface MTU 4096 bytes, BW 36864 Kbit, DLY 270 usec, rely 255/255, load 1/255 Encapsulation CHANNEL, loopback not set PCA adapter card Data transfer rate 4.5 Mbytes, number of subchannels 1 Last input never, output never, output hang never Last clearing of "show interface" counters never Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 1677 packets input, 0 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 1595 packets output, 0 bytes, 0 underruns 0 output errors, 0 collisions, 5 interface resets, 0 restarts 0 output buffer failures, 0 output buffers swapped out
  用"show interface channel 3/2"显示逻辑通道口状态.Router#sh int ch3/2Channel3/2 is up, line protocol is up Hardware is cyBus Channel Interface MTU 4472 bytes, BW 98304 Kbit, DLY 100 usec, rely 255/255, load 1/255 Encapsulation CHANNEL, loopback not set Virtual interface Last input 0:01:36, output 0:01:26, output hang never Last clearing of "show interface" counters never Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 19090 packets input, 686391 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 20314 packets output, 754513 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets, 0 restarts 0 output buffer failures, 0 output buffers swapped out
  用基于tcpip协议的文件传输命令是"show ext ch 3/0 csna oper"显示CSNA通道连接设备状态."stat"替代"oper"获得CSNA通道连接设备的统计值.确认CSNA通道连接设备状态为"setupComplet".Router#sh ext c3/0 csna Path Dv maxpiu time-delay length-delayCSNA 0100 E1 20470 10 20470Router#sh ext c3/0 csna oper Path Dv Status SlowDown maxpiu time-delay length-delayCSNA 0100 E1 setupComplet off 20470 10 20470
  用"show ext ch 3/2 conn llc"命令确定SAPs值和CIP上打开的连接.确认定义在XCA中的正确的SAP值在CIP internal Token Ring LAN adapter中已打开.SHANXI2#sh ext c3/2 conn llc LAN Token 0 Adapter 1 5808.0100.0000 No SAPs open on this interface Total : SAPs opened = 0 Connections active = 0
  如果CSNA通道连接设备状态是"setupComplet",正确的SAP(i.e.,SAP 08)打开在正确的CIP internalMAC adapter,进入第七步.否则,问题可能是PATH/DEVICEXCA Major Node.请检查通道地址定义是否正确.PATH/DEVICE正确,再在主机上"v net,act,id="命令确认XCA Major Node激活.Router#sh ext c3/0 csna oper Path Dv Status SlowDown maxpiu time-delay length-delayCSNA 0100 E1 Close off 20470 10 20470
  用"debug source-bridge"命令确定是否产生探测帧.如果确定以CIPinternal MAC地址为目的的探测帧被接收到,请打开"debugchannel vlan".
 
  用"show ext ch 3/2 lan"命令显示CIP internal MAC adapters.核实CIP internal MAC adapterCIP microcode确认.router#debug channel vlanrouter#show ext ch 3/2 lanLan TokenRing 0 source-bridge 1000 1 100 Adapno Mac Address Name Vcnum 0 4000.1234.0001 544 0041 ACK ... ... ... ...... INU
  如果CIP internal MAC adapters没有收到CIP的应答,("showext ch 3/2 lan"显示不是ACK而是CREPNDIND),表明CIPmicrocode没有承认CIP adapter配置命令.在这种情况下,RP不发送探测帧给CIP.
 
  如果CIP internal MAC adapters已经接收到CIP的应答,"showext ch 3/2 llc stat 4000.0008.0000",4000.0008.0000CIPinternalMAC address,检查是否收到CIP MAC adapter的检测命令和应答.
 
  如果正常,再用"show ext ch 3/2 llc stat4000.0008.0000 08"命令确认SAP是否接收到XIDs和应答.如果没有应答,可能是SwitchedMajor Node没被激活,IDBLK/IDNUM不正确,PU被占用.
 
  在下端路由器上"show dlsw"命令查看串口连接的SNA end station状态.参阅DLSw+ Troubleshooting.
  用"show llc2"显示当前已建立的LLC2链接.SHANXI2#sh llcLLC2 Connections: total of 1 connectionsChannel1/2 DTE: 5808.0100.0000 4000.4700.10c1 04 04 state NORMAL V(S)=38, V(R)=38, Last N(R)=38, Local window=7, Remote Window=127 akmax=3, n2=8, Next timer in 7520 xid-retry timer 0/0 ack timer 0/1000 p timer 0/1000 idle timer 7520/10000 rej timer 0/3200 busy timer 0/9600 akdelay timer 0/100 txQ count 0/200 RIF: 0630.0641.0020

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