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interfaces don not come up

  • 1.  interfaces don not come up

    Posted 12-18-2017 15:16

    Hello all


    I do not have much experience working with juniper and I'm having issues with one ex 4300, it is suposse that ex4300 will replace a cisco switch that is on production now, but when I tried to do the change there are several interfaces that don't not come up.  I think it is a mismatch issue between the configurations. As troubleshoot I ereased the speed and full duplex and I set the interfeces with negotiation-auto but did not work, also I erased the port security but not success. Any idea of what is the cause of this negotiation failed or incomplete.


    Also I was looking for a command to monitor or debug the messages of the interfaces without lucky so I will realy appreciate if you can share how can I monitor the interface


    Best regards

  • 2.  RE: interfaces don not come up

    Posted 12-19-2017 04:04

    If you are talking about simply getting link up on a physical port, typically you would set the port to the expectation of the client as you seem to have done.  Patience is also a key in explict port settings they can take some time to come up in some cases.


    With setting explicit speed and duplex you should also set the no-autonegotiation parameter to insure the port waits for the device to fully link up without falling back to autonegotiation.


    Removing the link speed and duplex with no settings should turn on gig autonegotiation by default.


    You can see messages on the port status changes in the messages log.


    show log messages


    You will need to know the ifIndex for the port you are testing which you can see in 

    show interface ge-0/0/0 | match ifindex


  • 3.  RE: interfaces don not come up

    Posted 12-19-2017 10:10

    Hi Folks,

    Please find some REAL GOOD pointers on this,


    Resolution Guide - EX - Verify/Troubleshoot Physical Interface




    [M/MX/T series] Troubleshooting Checklist - Ethernet Physical Interfaces




    Troubleshooting: 10-Gigabit Ethernet Port Stuck in Down State





  • 4.  RE: interfaces don not come up

    Posted 12-26-2017 19:19


    Below are the steps, I would recommend for troubleshooting:


    1. Make sure the correct fiber cables are being used between the two segments (MM or SM),


    2. Make sure to test the fiber the link running between the two segment using devices such as OTDR, to verify there is no significant amount of loss or cable breaks.


    3. Verify transceiver properties:



    show chassis pic fpc-slot 0 pic-slot 0


    FPC slot 0, PIC slot 0 information:

      Type                             24x10G-4x40G

      State                            Online    

      PIC version                 3.27

      Uptime 490 days, 14 hours, 59 minutes, 26 seconds


    PIC port information:

                             Fiber                    Xcvr vendor       Wave-    Xcvr

      Port Cable type        type  Xcvr vendor        part number       length   Firmware

      0    GIGE 1000SX       MM    FINISAR CORP.      FTLF8519P2BNL-J1  850 nm   0.0   

      1    GIGE 1000LX10     SM    FINISAR CORP.      FTLF1318P2BTL-J1  1310 nm  0.0   


    4. Check for the output of the Receiver signal average optical power, make sure the value is higher than 0 mW. Value of 0 indicates the receiving end is not receiving any optical signal from the remote end.



    show interfaces diagnostics optics ge-0/0/4  

    Physical interface: ge-0/0/4

        Laser bias current                        :  12.920 mA

        Laser output power                        :  0.2140 mW / -6.70 dBm

        Module temperature                        :  35 degrees C / 95 degrees F

        Module voltage                            :  3.2820 V

        Receiver signal average optical power     :  0.2452 mW / -6.10 dBm

        Laser bias current high alarm             :  Off

        Laser bias current low alarm              :  Off

        Laser bias current high warning           :  Off

        Laser bias current low warning            :  Off

        Laser output power high alarm             :  Off

        Laser output power low alarm              :  Off

        Laser output power high warning           :  Off

        Laser output power low warning            :  Off

        Module temperature high alarm             :  Off

        Module temperature low alarm              :  Off

        Module temperature high warning           :  Off

        Module temperature low warning            :  Off

        Module voltage high alarm                 :  Off

        Module voltage low alarm                  :  Off

        Module voltage high warning               :  Off

        Module voltage low warning                :  Off

        Laser rx power high alarm                 :  Off

        Laser rx power low alarm                  :  Off

        Laser rx power high warning               :  Off

        Laser rx power low warning                :  Off

        Laser bias current high alarm threshold   :  45.000 mA

        Laser bias current low alarm threshold    :  0.000 mA

        Laser bias current high warning threshold :  40.000 mA

        Laser bias current low warning threshold  :  0.400 mA

        Laser output power high alarm threshold   :  0.7940 mW / -1.00 dBm

        Laser output power low alarm threshold    :  0.0700 mW / -11.55 dBm

        Laser output power high warning threshold :  0.6310 mW / -2.00 dBm

        Laser output power low warning threshold  :  0.0890 mW / -10.51 dBm

        Module temperature high alarm threshold   :  93 degrees C / 199 degrees F

        Module temperature low alarm threshold    :  -10 degrees C / 14 degrees F

        Module temperature high warning threshold :  88 degrees C / 190 degrees F

        Module temperature low warning threshold  :  -5 degrees C / 23 degrees F

        Module voltage high alarm threshold       :  3.565 V

        Module voltage low alarm threshold        :  3.035 V

        Module voltage high warning threshold     :  3.500 V

        Module voltage low warning threshold      :  3.100 V

        Laser rx power high alarm threshold       :  0.5010 mW / -3.00 dBm

        Laser rx power low alarm threshold        :  0.0063 mW / -22.01 dBm

        Laser rx power high warning threshold     :  0.3980 mW / -4.00 dBm

        Laser rx power low warning threshold      :  0.0080 mW / -20.97 dBm



    5. Make sure the interface is not Admin disabled


    6. Make sure the interfaces is not disabled via STP


    7. Make sure the speed/duplex and MTU matches between the corresponding segments


    8. Make sure if there are any intermediary network devices such as media converters in between the segments. This one can be tricky.


    9. Check if there are any incrementing errors on the feed interfaces:


    show interfaces ge-0/0/4 extensive |match error


      Link-level type: Ethernet, MTU: 1514, MRU: 0, Speed: 1000mbps, BPDU Error: None, MAC-REWRITE Error: None, Loopback: Disabled, Source filtering: Disabled,

      Input errors:

        Errors: 0, Drops: 0, Framing errors: 0, Runts: 0, Bucket drops: 0, Policed discards: 0, L3 incompletes: 0, L2 channel errors: 0, L2 mismatch timeouts: 0,

        FIFO errors: 0, Resource errors: 0

      Output errors:

        Carrier transitions: 3, Errors: 0, Drops: 10947052, Collisions: 0, Aged packets: 0, FIFO errors: 0, HS link CRC errors: 0, MTU errors: 0,

        Resource errors: 0, Bucket drops: 0

        CRC/Align errors                         0                0

        FIFO errors                              0                0

        Output packet error count                                 0


    10. Try moving the existing fiber pair to a new pair if thats a possibility.


    11. Make sure to change optical transceiver to eliminate problems with transceiver (which is a rare issue, but could be possible).


    Hope this helps!!