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New Member

ASR 1K SFP Connectivity Issue

We are commisining new link on our router. SFP is connected but not coming up. Here is the interface ststus. Is this physical connectivity problem ot configuration negotion issue?


Thsi is a ASR 1K. I guess if its a physical coneectivty issue does it show notconnecte on the line in bracket? Or on router it doesent please help.


ITV-GRW-INET-RTR1B#show int gigabitEthernet 0/1/2
GigabitEthernet0/1/2 is down, line protocol is down
  Hardware is SPA-5X1GE-V2, address is f866.f2aa.e941 (bia f866.f2aa.e892)
  Description: ** Part of ether-channel to 6DG internet **
  MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not supported
  Full Duplex, 1000Mbps, link type is auto, media type is SX
  output flow-control is on, input flow-control is on
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input never, output never, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/375/0/0 (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
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 packets output, 0 bytes, 0 underruns

  • Small Business Switches

Hi raiden1987 ,  Have you



physical possibilities ? 

 - Bad cables

  -  Bad SFP.

 - Bad port


Have you checked the other side , if it is connected ?


If everything seems fine , you may need to open a TAC case in order to  investigate deep the issues with Hardware team  or end up in a RMA.


Hope this helps.


-Randy -

New Member

If your SFP has DOM support,

If your SFP has DOM support, you can verify the optical receive-signal from the other side. This is independant of establishing a link:

xxx#sh hw-module subslot 0/0 transceiver 0 status 
The Transceiver in slot 0 subslot 0 port 0 is enabled.
  Module temperature                        = +39.164 C
  Transceiver Tx supply voltage             = 3298.5 mVolts
  Transceiver Tx bias current               = 19904 uAmps
  Transceiver Tx power                      = -5.5 dBm
  Transceiver Rx optical power              = -12.4 dBm

For 1000Base-SX you should have a signal above -17 dBm. Levels below -30 dBm are typically interchanged (or broken) fibers.

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