网络常用故障排除命令
- 1、下载文档前请自行甄别文档内容的完整性,平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益,请联系客服反馈,我们会尽快为您处理(人工客服工作时间:9:00-18:30)。
常用故障排除命令(实用推荐)
常用故障排除命令(实用推荐)
1、ping命令排错
(1)Ping一下自己的地址,看看网卡安装是不是有问题。
(2)查看PC的TCP/IP协议是否有问题,ping127.0.01,看是否通。
(3)在路由器上ping与自己同属一部门且网关做在其它地方的方法
具体的操作为:
[NE05]ping –vpn XXX –a 14.12.124.254 14.12.125.254 (注:XXX为该VPN的名字,-a后面的地址为刚配置的部门B网关的地址,最后的地址是其它地方的部门B的网关地址,这两个网关地址绑定在同一个纵向MPLS VPN中)。
ping 14.12.125.254 : 56 data bytes, press CTRL_C to break
Reply from 14.12.125.254 : bytes=56 Sequence=1 ttl=250 time = 23 ms
Reply from 14.12.125.254 : bytes=56 Sequence=2 ttl=250 time = 23 ms
Reply from 14.12.125.254 : bytes=56 Sequence=3 ttl=250 time = 23 ms
Reply from 14.12.125.254 : bytes=56 Sequence=4 ttl=250 time = 23 ms
Reply from 14.12.125.254 : bytes=56 Sequence=5 ttl=250 time = 23 ms
--- 14.12.125.254 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
G704#ping –vrf xxx –source 14.12.124.254 14.12.125.254
2、 查看PC的网络设置是否正确
查看第一处的IP地址、子网掩码、网关地址及DNS设置是不是正确,并检查第一个default gateway 和第二处的gateway 是不是一样,如果不同,需要重新配置。
3、 显示设备接口状态
用命令display interface Ethernet 4/2/0.12(G704#show interface eth1/1.12) 显示如下:
[NE05]display interface Ethernet 4/2/0.12 (显示以太网4/2/0.12端口)
Ethernet4/0/0.12 current state : UP (当前的物理状态情况up)
Line protocol current state : UP (当前的协议状态up)
Description : to jiwei-hx (此端口描述)
The Maximum Transmit Unit is 1500 bytes, Hold timer is 10(sec) ( mtu值为1500)
IP Sending Frames' Format is PKTFMT_ETHNT_2, Hardware address is 00e0-fc1f-b904
Encapsulation dot1q Virtual LAN, Vlan number 1
Internet Address is 14.174.129.62/26 (本端口的ip地址)
Media type is twisted pair, loopback not set, promiscuous mode not set
100Mbps-speed mode, full-duplex mode, link type is autonegotiation (端口数率、全双工模式、匹配方式)
The maximum frame length is 1600
5 minutes input rate 0 bytes/sec, 0 packets/sec (5分钟内进方向包数量)
5 minutes output rate 0 bytes/sec, 0 packets/sec (5分钟内出方向包数量)
Input: 0 packets, 0 bytes 进方向
0 broadcasts, 0 multicasts 广播包数量、组播包数量
0 errors, 0 drops, 0 unknow protocol 错包数量、未知协议包数量
Output:0 packets, 0 bytes 出方向
0 broadcasts, 0 multicasts 广播
包数量、组播包数量
0 errors, 0 drops 错包数量、未知协议包数量
从上面我们可以看到:当前接口的物理连接是up的,没有问题,如果当前的物理状态为down,那么需要检查线路,看看线是不是坏了,如果线没有坏,需要检查当前的两个接口有没有问题,是不是接口坏了。
如果当前物理连接显示up ,协议显示down ,那么需要检查两边的通信协议是不是一样,如果不一样,需要配置成一样才可以通信。
如果以上都是好的,再看一下100Mbps-speed mode, full-duplex mode, link type is autonegotiation 两边是不是都是自协商的,有时候会协商不好,解决的方法就是两边都强制百兆全双工。
如果协商没有问,最后看一下input 和 output 有没有显示错误的信息,如果有,则需要检查光纤收发器,原因为光纤收发器的接口和路由器的接口不能协商好,解决的方法就是把光纤收发器和路由器的接口都强制成百兆全双工。
G704#show interface eth1/1.12
Interface eth1/1.12 is up, Line protocol is up
Internet address is 10.76.12.254/24 Broadcast 10.76.12.255
vlan ID 12
mtu 1500
Queueing strategy: 3-BAND fast fifo (default)
Output queue (size/max/drops) : 0/100/0
[S3026E]display interface Ethernet 0/3 显示端口0/3
Ethernet0/3 current state : UP 端口状态up
IP Sending Frames' Format is PKTFMT_ETHNT_2, Hardware address is 00e0-fc22-1b3b 端口mac地址及帧格式
The Maximum Transmit Unit is 1500 端口mtu值
Media type is twisted pair, loopback not set
Port hardware type is 100_BASE_TX 端口物理属性
Unknown-speed mode, unknown-duplex mode 端口数率及工作模式
Link speed type is autonegotiation, link duplex type is autonegotiation 端口协商方式
Flow-control is not supported 端口流控
The Maximum Frame Length is 1536 端口最大帧长度
Broadcast MAX-ratio: 100% 端口广播抑制
PVID: 12 端口pvlan id
Mdi type: auto 物理连线类型
Port link-type: access 端口工作模式(access、trunk)
Tagged VLAN ID : 12
Untagged VLAN ID : 12
Last 5 minutes input: 0 packets/sec 0 bytes/sec 0% 最后5分钟进方向数据包数量
Last 5 minutes output: 0 packets/sec 0 bytes/sec 0% 最后5分钟进方向数据包数量
input(total): 0 packets, 0 bytes 进方向总计
0 broadcasts, 0 multicasts 广播包总计、组播包总计
input(normal): - packets, - bytes 进方向正常包
- broadcasts, - multicasts 广播包、组播包
input: 0 input errors, 0 runts, 0 giants, - throttles, 0 CRC 进
方向各种错包
0 frame, - overruns, 0 aborts, 0 ignored, - parity errors
Output(total): 0 packets, 0 bytes 出方向总计
0 broadcasts, 0 multicasts, 0 pauses 广播包总计、组播包总计
Output(normal): - packets, - bytes 出方向正常包
- broadcasts, - multicasts, - pauses 广播包、组播包
Output: 0 output errors, - underruns, - buffer failures 出方向各种错包
0 aborts, 0 deferred, 0 collisions, 0 late collisions
0 lost carrier, - no carrier
从上面我们可以看到:当前接口的物理连接是up的,没有问题,如果当前的物理状态为down,那么需要检查线路,看看线是不是坏了,如果线没有坏,需要检查当前的两个接口有没有问题,是不是接口坏了。
如果当前物理连接显示up ,协议显示down ,那么需要检查两边的通信协议是不是一样,如果不一样,需要配置成一样才可以通信。
如果以上都是好的,再看一下100Mbps-speed mode, full-duplex mode, link type is autonegotiation 两边是不是都是自协商的,有时候会协商不好,解决的方法就是两边都强制百兆全双工。
如果协商没有问,最后看一下input 和 output 有没有显示错误的信息,如果有,则需要检查光纤收发器,原因为光纤收发器的接口和路由器的接口不能协商好,解决的方法就是把光纤收发器和路由器的接口都强制成百兆全双工。
Flex5010(config)#show port 3
---------------------------------------------------------------------------
Port:3 's Configuration Information
Link State : Down Port State : Enabled
Port Type : 100BaseTX Speed : 10
Autonegotiation : Enabled Duplex : Half
Flowcontrol : Disabled Learn State : Enabled
Port BPDU : Received
Port vlan ID : 2047
Port vlan Name : default
Port Summary : normal
---------------------------------------------------------------------------
4、 在交换机上查看用户或交换机是否正常连接到本设备上的方法
mac地址 该mac所在的vlan号 方式 该mac的端口 老化时间
MAC ADDR VLAN ID STATE PORT INDEX AGING TIME(s)
000f-e200-dedc 500 Learned Ethernet0/16 AGING
000f-e200-dedc 2 Learned Ethernet0/16 AGING
000f-e200-dedc 1 Learned Ethernet0/16 AGING
00e0-fc09-bcf9 1 Learned Ethernet0/16 AGING
--- 4 mac address(es) found ---
(举例:mac地址为00e0-fc24-b24a是在vlan 541中,通过ethernet0/18端口学习到的mac地址,状态为在线)
Flex5010(
config)#show fdb
------- Begin of Mac Address Table Information (all)-------
Mac address Port vlan name Flags
------------------ ---- ------------------------------ --------------------
00:05:3b:10:1c:b1 21 default Dynamic
00:05:3b:58:40:55 12 default Dynamic
00:e0:fc:09:bc:f9 24 default Dynamic
00:05:3b:10:1c:ff 22 default Dynamic
00:0f:e2:06:2a:0e 24 default Dynamic
Total 5 mac address entry showed.
MAC ADDR VLAN ID STATE PORT INDEX AGING TIME(s)
00e0-fc22-8e65 1003 Learned Ethernet0/24 AGING
00e0-fc22-8e65 301 Learned Ethernet0/24 AGING
00e0-fc22-8e65 1 Learned Ethernet0/24 AGING
--- 3 mac address(es) found on port Ethernet0/24 ---
Flex5010(config)#show fdb
MAC ADDR VLAN ID STATE PORT INDEX AGING TIME(s)
000f-e200-dedc 2 Learned Ethernet0/16 AGING
00e0-fc0a-7f12 2 Learned GigabitEthernet1/1 AGING
000f-e201-272f 2 Learned GigabitEthernet1/1 AGING
00e0-fc22-8e60 2 Learned GigabitEthernet1/1 AGING
00e0-fc0a-aac7 2 Learned GigabitEthernet1/1 AGING
000c-7623-1efc 2 Learned GigabitEthernet1/1 AGING
--- 6 mac address(es) found in vlan 2 ---
Flex5010(config)#show fdb vlan v2
------- Begin of Mac Address Table Information (vlan:[v2])-------
Mac address Port vlan name Flags
------------------ ---- ------------------------------ --------------------
00:05:3b:58:40:55 12 v2 Dynamic
00:0f:e2:06:2a:0e 24 v2 Dynamic
00:05:3b:59:20:16 0 v2 System L3 Permanent
00:0f:e2:06:2a:8d 23 v2 Dynamic
------------------ ---- ------------------------------ --------------------
Total 4 mac address entry showed.
---------- End of Mac Address Table Information ----------
动态学习到的mac地址)
MAC ADDR VLAN ID STATE PORT INDEX AGING TIME(s)
000f-e200-dedc 500 Learned Ethernet0/16 AGING
000f-e200-dedc 2 Learned Ethernet0/16 AGING
00e0-fc24-b24a 541 Learned Ethernet0/18 AGING
00e0-fc22-8ded 300 Learned Ethernet0/21 AGING
00e0-fc22-8ded 1 Learned Ethernet0/21 AGING
00e0-fc09-bcf9 1 Learned GigabitEthernet1/1 AGING
--- 6 mac address(es) found ---
Flex5010(config)#show fdb
5、显示arp表项
VlanID IP地址 MAC地址 类型 在那个端口
VLAN IPAddress MAC_address Type Interface
2 192.168.15.252 00e0-fc0a-8a5d Dynamic GigabitEthernet1/0/0
(通过动态学习到)
2 192.168.15.42 0050-bafd-9417 Dynamic GigabitEthernet5/1/1
2 192.168.15.99 00e0-fc2d-dfa9 Dynamic GigabitEthernet5/1/1
2 192.168.15.39 0050-baf7-6ee5 Dynamic GigabitEthernet9/0/0
2 192.168.15.15 0050-baf7-6c43 Dynamic Ethernet3/0/4
Flex5010(config)#show arp
ARP TABLE LIST:
IP ADDRESS MAC ADDRESS TYPE REFERENCE USE4 v24 Dynamic
-------------------------------------------------------------------------- Dynamic
10.79.13.105 00:06:1b:d3:72:3e DYNAMIC
00:0d:87:6d:70:d9 11 v212
10.79.21.103 00:20:ed:9e:00:ca DYNAMIC 0 0
00:10:5c:fc:e8:58 21 v212
10.79.24.103 00:20:ed:16:58:62 DYNAMIC 0 0
VLAN IPAddress MAC_address Type Interface
2 192.168.15.39 0050-baf7-6ee5 Dynamic GigabitEthernet9/0/0
2 192.168.15.83 0050-bafd-18b4 Dynamic GigabitEthernet9/0/0
2 192.168.15.98 00e0-fc2d-ac99 Dynamic GigabitEthernet9/0/0
Flex5010(config)#show arp
VLAN IPAddress MAC_address Type Interface
2 192.168.15.252 00e0-fc0a-8a5d Dynamic GigabitEthernet1/0/0
2 192.168.15.42 0050-bafd-9417 Dynamic GigabitEthernet5/1/1
2 192.168.15.99 00e0-fc2d-dfa9 Dynamic GigabitEthernet5/1/1
Flex5010(config)#show arp
VLAN IPAddress MAC_address Type Interface
2 192
.168.15.252 00e0-fc0a-8a5d Dynamic GigabitEthernet1/0/0
2 192.168.15.42 0050-bafd-9417 Dynamic GigabitEthernet5/1/1
2 192.168.15.99 00e0-fc2d-dfa9 Dynamic GigabitEthernet5/1/1
2 Flex5010(config)#show arp
6、清除接口统计
Flex5010(config)#clear counter all
将该接口的统计信息初始化。
7、查看CPU的工作状态
CPU busy status:
21% in last 5 seconds
17% in last 1 minute
18% in last 5 minutes
Flex5010(config)#show cpu usage
cpu usage: 9%
8、显示设备的系统信息
Flex5010(config)#show tech-support
显示该设备的所有技术支持信息。
9、显示路由表
Routing Table: public net
Destination/Mask Protocol Pre Cost Nexthop Interface
0.0.0.0/0 STATIC 60 0 192.168.X.254 Vlan-interface2
10.1.3.0/24 DIRECT 0 0 10.1.3.254 vlanif3
10.1.11.254/32 DIRECT 0 0 127.0.0.1 InLoopBack0
192.168.X.0/24 DIRECT 0 0 192.168.X.6 Vlan-interface2
Flex5010(config)#show ip route
Codes: C - connected, S - static, R - RIP, O - OSPF,
> - Selected route, * - Selected nexthop
S>* 0.0.0.0/0 [1/0] via 192.168.1.238, vlan1000
C>* 10.164.10.8/30 is directly connected, vod
10、显示VPN的路由表
G704#show ip route vrf ABC