步骤:
1.先运行,porterrshow 查看口状态，然后'statsclear' and 'slotstatsclear'
2.查看:porterrshow,看下port 口的情况
3.收集supportshow ,supportsave
4.查看sfpshow -all 可以看23口倒数第二行RX Power状态，若较大就正常
sfpshow -all :
=============
Port 0:
=============
Identifier: 3 SFP
Connector: 7 LC
Transceiver: 540c402000000000 200,400,800_MB/s M5,M6 sw Inter_dist
Encoding: 1 8B10B
Baud Rate: 85 (units 100 megabaud)
Length 9u: 0 (units km)
Length 9u: 0 (units 100 meters)
Length 50u: 5 (units 10 meters)
Length 62.5u:3 (units 10 meters)
Length Cu: 0 (units 1 meter)
Vendor Name: BROCADE
Vendor OUI: 00:05:1e
Vendor PN: 57-1000012-01
Vendor Rev: A
Wavelength: 850 (units nm)
Options: 001a Loss_of_Sig,Tx_Fault,Tx_Disable
BR Max: 0
BR Min: 0
Serial No: UAA210473397682
Date Code: 101127
DD Type: 0x68
Enh Options: 0xf0
Status/Ctrl: 0x92
Alarm flags[0,1] = 0x0, 0x0
Warn Flags[0,1] = 0x0, 0x40
Alarm Warn
low high low high
Temperature: 34 Centigrade -15 100 -10 95
Current: 7.112 mAmps 2.000 8.500 2.000 8.500
Voltage: 3286.1 mVolts 2800.0 3800.0 2970.0 3630.0
RX Power: -7.2 dBm (190.9 uW) 0.0 uW 6550.0 uW 49.0 uW 1100.0 uW
TX Power: -2.3 dBm (588.7 uW) 50.0 uW 800.0 uW 100.0 uW 700.0 uW
5.若还是很小，原来：-16.3 dBm (23.2 uW)，更换光纤线，再重复上面的步骤
