局域网故障的诊断与排除 (9).ppt

1、交换机常见问题分析路由器常见问题分析客户端常见问题分析本章内容交换机常见问题分析路由器常见问题分析客户端常见问题分析课程议题故障现象故障分析故障现象故障分析故障现象故障分析故障分析故障现象故障现象故障现象VLAN20VLAN30192.168.2.8VLAN20192.168.1.1VLAN30192.168.2.1switchAswitchB故障分析故障现象故障分析分析：交换机保存配置文件的名称是config.text，保存VLAN配置文件的名称为vlan.dat，这两者均保存在FLASH中。当删除了vlan.dat只是将创建的VLAN及名称删除，并没有删除VLAN的成员所属关系。所以如果只

2、删vlan.dat，而不删除config.text或相应的配置，则已经被分配到某些VLAN的端口就不会在VLAN 1中出现。解决：此时应用show run来查看一下，这几个接口均属于哪个VLAN，然后进入这几个物理接口，用no switchport access vlan来清除其与已删除VLAN的所属关系。交换机常见问题分析路由器常见问题分析客户端常见问题分析课程议题故障现象故障分析故障现象故障分析故障现象故障分析故障现象172.16.1.0/24PC1PC2172.16.2.0/24172.16.3.0/24.1.11.2.22Router1Router2.1(DCE).2(DTE)图7-2

3、-1故障分析故障分析Router1#show interface serial 0Serial0 is up,line protocol is down Hardware is HDLC4530A Internet address is 172.16.2.1/24 MTU 1500 bytes,BW 2048 Kbit,DLY 20000 usec,rely 255/255,load 1/255 Encapsulation HDLC,loopback not set,keepalive set(10 sec)Last input never,output never,output hang n

4、ever Last clearing of show interface counters never Input queue:0/75/0(size/max/drops);Total output drops:0 Queueing strategy:weighted fair Output queue:0/64/0(size/threshold/drops)Conversations 0/0(active/max active)Reserved Conversations 0/0(allocated/max allocated)5 minute input rate 0 bits/sec,0

5、 packets/sec 5 minute output rate 0 bits/sec,0 packets/sec 0 packets input,0 bytes,0 no buffer Received 0 broadcasts 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,8 interface resets 0 output buffer failures,0 output buffers

6、 swapped out 0 carrier transitions DCD=down DSR=down DTR=down RTS=down CTS=down故障分析故障解决故障现象172.16.1.0/24PC1PC2172.16.2.0/24172.16.3.0/24.1.11.1.2.2.22Router1Router2故障分析当使用show run看到以下配置：Router1#show running-config !显示路由器Router1的全部配置Building configuration.Current configuration:!version 6.14(2)!hostna

7、me Router1!ip subnet-zero!interface FastEthernet0 ip address 172.16.1.1 255.255.255.0!interface Serial0 ip address 172.16.2.1 255.255.255.0 clock rate 64000!interface Serial1 no ip address shutdown!ip classless故障分析ip route 172.16.1.0 255.255.255.0 172.16.2.2!line con 0line aux 0line vty 0 4 login!en

8、d故障分析Router2#show running-config !显示路由器Router2的全部配置Building configuration.Current configuration:!version 6.14(2)!hostname Router2!ip subnet-zero!interface FastEthernet0 ip address 172.16.3.2 255.255.255.0!interface Serial0 ip address 172.16.2.2 255.255.255.0!interface Serial1 no ip address shutdown!

9、ip classless故障分析ip route 172.16.3.0 255.255.255.0 172.16.2.1!line con 0line aux 0line vty 0 4 login!end发现在配置静态路由时都指向了本端直连的网段。在配置静态路由时，要指定如何到达非直连的网段。故障解决故障现象故障分析当在配置了NAT的路由器上查看R1#sh ip nat translations Pro Inside global Inside local Outside local Outside global转换表中是空的，则怀疑是配置错误。通过show run查看配置文件。Curren

10、t configuration:version 6.14(2)hostname R1ip subnet-zerointerface FastEthernet0 ip address 172.18.3.254 255.255.255.0 ip nat outsideinterface FastEthernet1ip address 200.24.5.8 255.255.255.0 ip nat insideinterface FastEthernet2 no ip address shutdowninterface FastEthernet3 no ip address shutdowninte

11、rface Serial0no ip address shutdowninterface Serial1 no ip address shutdown故障分析ip nat pool to-internet 200.24.5.8 200.24.5.8 netmask 255.255.255.0ip nat inside source list 1 pool to-internet overloadip classlessaccess-list 1 permit 172.18.3.0 0.0.0.255!line con 0line aux 0line vty 0 4 login!故障解决交换机常见问题分析路由器常见问题分析客户端常见问题分析课程议题故障现象故障现象故障分析 打开“控制面板网络”项，双击tcp/ip的属性，检查ip地址、dns、配置、网关等均设置正确。检查IE浏览器的“连接”一项，不要设置为“用代理服务器连接”，交换机常见问题分析路由器常见问题分析客户端常见问题分析课程回顾