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从设备上查看光衰减

光纤交换机在远距离传输时对于光衰减有一定要求,当光纤衰减过大,两端的接口将不能UP。一般在-5dbm至+5db之间。如下图,以Cisco MDS 9124光纤交换机为例

dbm1

进入设备的CONSOLE控制台,使用show interface fc x/x transceiver details命令可以查看某个端口的光衰减信息,以1/24为例,如下:

san-emc-01(config-if)# show interface fc 1/24 transceiver details 
fc1/24 sfp is present
    Name is OEM            
    Manufacturer’s part number is SFP-4G-ZX      
    Revision is 1.1
    Serial number is JUT102702FR    
    FC Transmitter type is long wave laser
    FC Transmitter supports long distance link length
    Transmission medium is single mode (SM) laser
    Supported speeds are – Min speed: 1000 Mb/s, Max speed: 4000 Mb/s
    Nominal bit rate is 4300 Mb/s
    Link length supported for 9/125mm fiber is 40.255 km
    Cisco extended id is unknown (0x0)

    No tx fault, no rx loss, in sync state, diagnostic monitoring type is 0x58
    SFP Diagnostics Information:
—————————————————————————-
                                     Alarms                  Warnings
                                High        Low         High          Low
—————————————————————————-
  Temperature  22.98 C        100.00 C    -45.00 C     95.00 C      -40.00 C
  Voltage       3.32 V          3.60 V      3.00 V      3.50 V        3.10 V
  Current      26.00 mA        80.00 mA    12.00 mA    75.00 mA      10.00 mA
  Tx Power     2.48 dBm        6.00 dBm   -5.00 dBm    5.00 dBm     -4.00 dBm
  Rx Power     -4.54 dBm       -1.00 dBm  -21.02 dBm   -2.00 dBm    -20.00 dBm
  Transmit Fault Count = 0
—————————————————————————-
  Note: ++  high-alarm; +  high-warning; –  low-alarm; -  low-warning

从上表中可以看出,Tx方向的衰减为2.48dBm,Rx的衰减为-4.54dBm,属于正常范围内。

 

以太网交换机也可以通过命令来查看光模块上的衰减,如H3C交换机,通过命令dis transceiver diagnosis interface G x/x/x来查看,如下:

[waiwang-center-h3c7510] dis transceiver diagnosis interface GigabitEthernet 0/0/6
GigabitEthernet0/0/6 transceiver diagnostic information:
  Current diagnostic parameters:
    Temp(°C)  Voltage(V)  Bias(mA)  RX power(dBm)  TX power(dBm)
    43              3.49            8.11          -5.18                 -4.71

华为交换机通过如下命令查看:

display transce inter g 1/0/23 version

 

 

华三交换机也可以通过以下命令查看光模块是否为真货,

[waiwang-center-h3c7510]dis transceiver manuinfo interface g0/0/30
GigabitEthernet0/0/30 transceiver manufacture information:
  Manu. Serial Number : 210231a562x08b009229
  Manufacturing Date  : 2008-11-22
  Vendor Name         : H3C

Vendor Name为H3C,即为真货。也可以去http://channel.h3c.com/channel/system/SearchTrueCode.jsp,输入上面显示的序列号,这里为210231a562x08b009229,来查询是否为真货。

Cisco wlc5508无线AP控制器去除强制DHCP认证

最近碰到一个故障,一台笔记本通过Cisco无线AP来连接网络,IP通过思科核心交换机获取。现在想把这台笔记本手动设定个同网段的IP,但设置后网络不通。

下来做个测试:准备跳过AP,直接将笔记本接在核心交换机上,然后设置为手动,网络正常。所以判断为Cisco的AP控制上的做了限制,下联客户端通过AP联网时强制DHCP。

Cisco wlc5508没接触过,只能进界面寻找相似的选项,最后试验下来,将DHCP Addr. Assignment选项的Required的钩去掉,如下图所示,这样操作后即可以去除强制DHCP的认证限制。

 

Cicso Catalyst 3750-E交换机enable密码忘记后的恢复

一台Cicso Catalyst 3750-E交换机忘记enable密码后无法进入调试,只能想办法将密码去除,但需保留原来交换机的配置。

步骤如下:

1、将交换机console口与电脑相连,再按住交换机面板前的“mode”键,然后重启交换机,直到面板的”STAT”灯亮,放手。如下图。

2、此时会出现如下菜单,依次输入flash_init,load_helper,然后重命名配置文件名称,最后输入boot重启交换机,操作如下:

The system has been interrupted prior to initializing the
flash filesystem.  The following commands will initialize
the flash filesystem, and finish loading the operating
system software:

    flash_init
    load_helper
    boot

switch: flash_init
Initializing Flash…
flashfs[0]: 4 files, 1 directories
flashfs[0]: 0 orphaned files, 0 orphaned directories
flashfs[0]: Total bytes: 15998976
flashfs[0]: Bytes used: 8282624
flashfs[0]: Bytes available: 7716352
flashfs[0]: flashfs fsck took 11 seconds.
…done Initializing Flash.
Boot Sector Filesystem (bs) installed, fsid: 3
Setting console baud rate to 9600…

switch: load_helper

switch: dir flash:
Directory of flash:/

2    -rwx  8276561  <date>  c3750-ipservices-mz.122-37.SE.bin
3    -rwx  616       <date>     vlan.dat
4    -rwx  5         <date>       private-config.text
6    -rwx  3027      <date>     config.text

7716352 bytes available (8282624 bytes used)

switch: rename flash:config.text flash:config.text.old
switch: boot
Loading “flash:/c3750-ipservices-mz.122-37.SE.bin”…@@@@

3、重启后进入系统进行如下操作

Would you like to enter the initial configuration dialog? [yes/no]: no   //选择no
 
Would you like to terminate autoinstall? [yes]:     //选择yes

还原配置文件名称,并复制配置文件至running中
Switch>en
Switch#rename flash:config.text.old flash:config.text
Switch#copy flash:config.text system:running-config

进入配置模式,去除enable密码,并保存至start-config中
c3750#configure terminal
c3750(config)#no enable password
c3750(config)#exit
c3750#wr memory
00:04:04: %SYS-5-CONFIG_I: Configured from console by console
Building configuration…
[OK]

这样,交换机的enable密码就去除完成了。

CISCO 4507R根据IP地址查找端口,并使用4/46口来镜像此端口

首先找出10.0.0.9的IP地址所在的端口,然后制作10.0.0.9服务器的镜像口->fastethernet4/46,使之可以查看10.0.0.9上的具体数据包信息。

操作步骤:

1、找出10.0.0.9的MAC地址

Switch#ping 10.0.0.9

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.0.9, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms
Switch#sh arp | in 10.0.0.9
Internet  10.0.0.9                4   0014.5e19.8345  ARPA   Vlan1
Internet  10.0.0.92               0   0019.bbdc.1d1f  ARPA   Vlan1
Internet  10.0.0.93               0   001e.4f98.0934  ARPA   Vlan1

2、查看MAC地址0014.5e19.8345的相应端口,显示为在fast4/23端口上

Switch#show mac-address-table address 0014.5e19.8345
Unicast Entries
 vlan   mac address     type        protocols               port
——-+—————+——–+———————+——————–
   1    0014.5e19.8345   dynamic ip                     FastEthernet4/23

3、制作fast4/23的镜像端口->fast4/46

Switch(config)#monitor session 1 source interface fastEthernet 4/23
Switch(config)#monitor session 1 destination interface fastEthernet 5/46

这样,就完成了从查找端口到制作镜像口的操作。