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1000BaseSX SFP GIG port errors - DOWN/DOWN. Rx power low alarm; Operating value: -25.7 dBm

I have a problem with 2 switches that connect via gig ports using SX MM fibre SFPs.

Currently the access switch is down / down and the Distribution switch (uplink) is showing errors in the log.

Could someone please help me determine if the fault is with the SFPs / switch or the fibre cabling.

 

Distribution Switch - cisco WS-C3750X-12S running IOS 12.2(55)SE8

NAME: "GigabitEthernet1/0/4", DESCR: "1000BaseSX SFP"
PID: GLC-SX-MMD          , VID: V01  , SN: FNS191519KR

interface GigabitEthernet1/0/4
 description MM 1G Fibre link to Kitchen, Access Switch Gi0/11 **
 switchport trunk encapsulation dot1q
 switchport mode trunk
end


sjdcs-mgambpr11#sh int gig1/0/4    
GigabitEthernet1/0/4 is down, line protocol is down (notconnect)
  Hardware is Gigabit Ethernet, address is e865.496c.ee84 (bia e865.496c.ee84)
  Description: (ML) **MM 1G Fibre link to Kitchen, sjdcs-mgambpr13 Gi0/11 **
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not set
  Full-duplex, 1000Mb/s, link type is auto, media type is 1000BaseSX SFP
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 1d10h, output 1d10h, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     414250 packets input, 78140140 bytes, 0 no buffer
     Received 121229 broadcasts (121227 multicasts)
     0 runts, 0 giants, 0 throttles
     8505 input errors, 340 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 121227 multicast, 0 pause input
     0 input packets with dribble condition detected
     8989428 packets output, 777832935 bytes, 0 underruns
     0 output errors, 0 collisions, 2 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out
    
    
     .Jul 28 03:16:33.280 ACST: %SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/4: Rx power low alarm; Operating value: -26.0 dBm, Threshold value: -21.0 dBm.
.Jul 28 03:26:33.636 ACST: %SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/4: Rx power low alarm; Operating value: -25.7 dBm, Threshold value: -21.0 dBm.
.Jul 28 03:36:33.992 ACST: %SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/4: Rx power low alarm; Operating value: -26.0 dBm, Threshold value: -21.0 dBm.
.Jul 28 03:46:34.340 ACST: %SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/4: Rx power low alarm; Operating value: -25.7 dBm, Threshold value: -21.0 dBm.
.Jul 28 03:56:34.687 ACST: %SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/4: Rx power low alarm; Operating value: -26.2 dBm, Threshold value: -21.0 dBm.
.Jul 28 04:06:35.043 ACST: %SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/4: Rx power low alarm; Operating value: -25.8 dBm, Threshold value: -21.0 dBm.
.Jul 28 04:16:35.399 ACST: %SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/4: Rx power low alarm; Operating value: -26.2 dBm, Threshold value: -21.0 dBm.
.Jul 28 04:26:35.746 ACST: %SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/4: Rx power low alarm; Operating value: -26.0 dBm, Threshold value: -21.0 dBm.
.Jul 28 04:36:36.102 ACST: %SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/4: Rx power low alarm; Operating value: -26.0 dBm, Threshold value: -21.0 dBm.
.Jul 28 04:46:36.458 ACST: %SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/4: Rx power low alarm; Operating value: -26.0 dBm, Threshold value: -21.0 dBm.
.Jul 28 04:52:55.632 ACST: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/4, changed state to down
    
    

Access Switch - cisco WS-C2960CX-8TC-L running IOS 15.2(3)E !!!CURRENTLY UNACCESSIBLE SO CANNOT PROVIDE ANY MORE INFORMATION THAN BELOW, SORRY!!!

GigabitEthernet0/11      1000BaseSX SFP       GLC-SX-MMD

interface GigabitEthernet0/11
 description ML **MM Fibre link to Control Room Gi1/0/4**
 switchport mode trunk

 

Many thanks!

3 REPLIES 3
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Hall of Fame Community Legend

8505 input errors, 340 CRC, 0 frame, 0 overrun, 0 ignored

Very obvious Layer 1 issue.  Check the fibre optic cable & module.  Being a multi-mode run, do a visible-light test to determine if there is a snap in the link.

Highlighted

Thanks Leo... I know it is a layer 1 issue, but my question was more around if the logs would help in determining if it was specifically the SFP or fibre cabling itself.

I was hoping to find out remotely as the site is in a regional location (5 hours drive). I will just have to take a couple of everything and test.

 

"Could someone please help me determine if the fault is with the SFPs / switch or the fibre cabling."

Highlighted
Hall of Fame Community Legend

My honest opinion, is I can't determine if it's the SFP or the fibre optic run or patch cable.   DOM SFP can't do OTDR test.  

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