第十节 故障诊断.ppt

1、第十节 故障诊断,故障定义,信息收集,分析原因,建立计划,实施计划,观察结果,重复执行,总题解决 总结经验,现象消失,末解决,10.0.0.5/24,10.0.0.6/24,10.0.0.1/24,11.0.0.1/24,11.0.0.2/24,172.16.0.1/30,172.16.0.2/30,Fa0/0,Fa0/1,Fa0/1,Fa0/0,Fa0/24,Fa0/24,故障诊断的实例,9.1 发送方故障诊断,数据包封装过程,数据转发过程,报文发送处理,查下一跳mac,目的与源地址比较,数据,封装传输层包头,封装网络层包头,下一跳IP,查找目的mac,查找成功,封装链路层,发送数据,链路层

2、地址,本地,远程,查路由表,无,无,有,有,Arp请求,得到,丢弃数据,丢弃数据,成功,否,网络层信息检查1,PC机上的 ipconfig/all,2、跨网段通信则网关ip是否正确,1、源、目的ip是否正确,3、基于域名通信查DNS是否正常工作,交换机或路由器show ip int bri,网络层信息检查2,Router#show ip interface brief Interface IP-Address OK? Method Status Protocol FastEthernet0/0 10.0.0.5 YES manual up up Serial1/0 20.0.0.6 YES m

3、anual up up Serial1/1 unassigned YES unset administratively down down Serial1/2 unassigned YES unset administratively down down Serial1/3 unassigned YES unset administratively down down Router#,Router#show int s1/0 Serial1/0 is up, line protocol is up Hardware is M4T Internet address is 20.0.0.6/24

4、MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation FRAME-RELAY, crc 16, loopback not set Keepalive set (10 sec) Restart-Delay is 0 secs .,网络层信息检查3,Router#show ip route Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, E

5、X - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user stat

6、ic route o - ODR, P - periodic downloaded static route Gateway of last resort is not set 100.0.0.0/32 is subnetted, 1 subnets O 100.0.0.1 110/2 via 10.0.0.4, 00:00:09, FastEthernet0/0 20.0.0.0/24 is subnetted, 1 subnets C 20.0.0.0 is directly connected, Serial1/0 10.0.0.0/24 is subnetted, 1 subnets

7、C 10.0.0.0 is directly connected, FastEthernet0/0 30.0.0.0/24 is subnetted, 1 subnets S 30.0.0.0 1/0 via 10.0.0.4,网络层信息检查4,C:route print = Interface List 0 x1 . MS TCP Loopback interface 0 x3 .00 13 02 6d 24 40 . Intel(R) PRO/Wireless 3945ABG Network Connect - 数据包计划程序微型端口 0 x20002 .66 66 66 66 66 66

8、 . Broadcom 440 x 10/100 Integrated Controlle 数据包计划程序微型端口 = = Active Routes: Network Destination Netmask Gateway Interface Metric 0.0.0.0 0.0.0.0 192.168.102.1 192.168.102.11 20 127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1 192.168.102.0 255.255.255.0 192.168.102.11 192.168.102.11 20 192.168.102.11 255.

9、255.255.255 127.0.0.1 127.0.0.1 20 192.168.102.255 255.255.255.255 192.168.102.11 192.168.102.11 20 224.0.0.0 240.0.0.0 192.168.102.11 192.168.102.11 20 255.255.255.255 255.255.255.255 192.168.102.11 192.168.102.11 1 255.255.255.255 255.255.255.255 192.168.102.11 3 1 Default Gateway: 192.168.102.1 =

10、 Persistent Routes: None C:,数据链路层信息检查,1、直接通信（即本网段内通信） 查看是否能得到目标设备的物理地址即MAC,Pc: arp -a,交换机路由器上：show arp,2、非直接通信（即本网段内通信） 查看是否能得到中继设备及网关或下一跳路由器MAC,物理层检查1,1、接口否是工作正常,Router#show interfaces f0/0 FastEthernet0/0 is up, line protocol is up Hardware is AmdFE, address is cc05.0360.0000 (bia cc05.0360.0000)

11、Internet address is 10.0.0.5/24 MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set 。 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 32 packets input, 7941 bytes Received 27 b

12、roadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog 0 input packets with dribble condition detected 151 packets output, 15913 bytes, 0 underruns 0 output errors, 0 collisions, 1 interface resets 0 babbles, 0 late collision, 0 deferred 。,物理层检查2,2、

13、线缆连接正常否,同层设备交叉线,不同层设备直连线,9.2 接收方故障诊断,数据接收处理,数据包解封装,报文接收处理,报文目的,接口地址,广播地址,组播地址,是/否相同,协议字段,上层协议栈,是,否,是/否有转发,丢弃,否,是,查mac表,重复流程,解封装,功能开,功能开,报文到达,成功,转发,设备配置看是否转发,是,数据链路层检查1,1、查看接收到的报文CRC。,Router#show int fa0/0 FastEthernet0/0 is up, line protocol is up Hardware is AmdFE, address is cc05.0360.0000 (bia cc

14、05.0360.0000) Internet address is 10.0.0.5/24 MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 。 。 93 packets input, 27598 bytes Received 88 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog 0 input packets with dribble condition detected 540 packets output, 54961 by