Expand all | Collapse all

10Gb SFP+ Autonegotiation

  • 1.  10Gb SFP+ Autonegotiation

    Posted 10-23-2017 02:57

    I'm having trouble getting autonegotiation status on a 10Gb SFP+ port on a QFX5100. Whether autonegotiation is set or not I don't see anything that indicates if autoneg is on, or what the outcome was.


    1Gb-T, I see status, partner, and local:

    Physical interface: ge-0/0/0, Enabled, Physical link is Up
      Interface index: 659, SNMP ifIndex: 558, Generation: 150
      Link-level type: Ethernet, MTU: 1514, MRU: 0, Speed: 1000 Mbps, Duplex: Auto,
      Autonegotiation information:
        Negotiation status: Complete
        Link partner:
            Link mode: Full-duplex, Flow control: Symmetric, Remote fault: OK,
            Link partner Speed: 1000 Mbps
        Local resolution:
            Flow control: None, Flow control tx: None, Flow control rx: None,
            Remote fault: Link OK


    10Gb-SR, Nothing:

    Physical interface: xe-0/0/28, Enabled, Physical link is Up
      Interface index: 686, SNMP ifIndex: 548, Generation: 179
      Link-level type: Ethernet, MTU: 1514, MRU: 0, Speed: 10Gbps, BPDU Error: None, MAC-REWRITE Error: None,
      Loopback: Disabled, Source filtering: Disabled, Flow control: Disabled, Media type: Fiber


    test@test> show configuration interfaces xe-0/0/28 
    ether-options {
    unit 0 {
        family ethernet-switching {
            interface-mode trunk;
            vlan {
                members [ 160-162 260 666 680 780 999 ];


    Is this info somewhere else?

  • 2.  RE: 10Gb SFP+ Autonegotiation

    Posted 10-23-2017 03:37

    Are you using the command "run show interfaces xe-< > extensive" ?

    You should be able to see the duplex and negotiated speed.


    If you at all you would want to confirm it for live traffic..You may use command of "run monitor interface xe-< >"...


    It will anyways display the negotiated speed of the interfaces.

  • 3.  RE: 10Gb SFP+ Autonegotiation

    Posted 10-23-2017 04:25

    Yes, it is with extensive option. I don't see negotiation information in monitor interface, it simply shows interface speed.


    test                   Seconds: 123                 Time: 11:23:15
                                                             Delay: 0/0/102
    Interface: xe-0/0/28, Enabled, Link is Up
    Encapsulation: Ethernet, Speed: 10000mbps
    Traffic statistics:                                              Current delta
      Input bytes:                       316 (0 bps)                          [74]
      Output bytes:               1710720527 (62641024 bps)             [91377479]
      Input packets:                       4 (0 pps)                           [1]
      Output packets:                2077295 (11380 pps)                  [115407]
    Error statistics:
      Input errors:                        0                                   [0]
      Input drops:                         0                                   [0]
      Input framing errors:                0                                   [0]
      Policed discards:                    0                                   [0]
      L3 incompletes:                      0                                   [0]
      L2 channel errors:                   0                                   [0]
      L2 mismatch timeouts:                0                                   [0]
      Carrier transitions:                21                                   [1]
      Output errors:                       0                                   [0]
      Output drops:                        0                                   [0]
      Aged packets:                        0                                   [0]
    Active alarms : None
    Active defects: None
    Input MAC/Filter statistics:
      Unicast packets                      0                                   [0]
      Broadcast packets                    0                                   [0]
      Multicast packets                    4                                   [1]
      Oversized frames                     0  Packet reject count              [0]
    Next='n', Quit='q' or ESC, Freeze='f', Thaw='t', Clear='c', Interface='i'

  • 4.  RE: 10Gb SFP+ Autonegotiation

    Posted 10-23-2017 06:05

    This may be because per the 10GE standard ONLY auto-neg is supported.  Some implementations allow for fixing speed and duplex, but this is against the standard (sort of I believe).  Anyway, if only auto-neg is allowed/supported why show it?

  • 5.  RE: 10Gb SFP+ Autonegotiation

    Posted 10-23-2017 06:06

    BTW, you are getting out packets, so what is at other end of this link, and what does it show?

  • 6.  RE: 10Gb SFP+ Autonegotiation

    Posted 10-23-2017 07:50


    Juniper allows for auto negotiation to be turned off:




    but I agree what’s normal or not isn’t clear. Throw 10Gb-T in and it’s less clear.

    The issue is that the port goes down when the attached device fully boots up. I have no access to the device but the vendor has asked that I turn off negotiation. I can and have but there is no difference in output when I do. Ultimately I’m looking for something I can send back to them that indicates negotiation status.

  • 7.  RE: 10Gb SFP+ Autonegotiation

    Posted 10-24-2017 11:33

    Just FYI, I would not trust that link to be 100% accurate across all products.  For example, the 10GE interfaces on EX4300 Uplink Module can NOT be set with auto-neg disabled.



  • 8.  RE: 10Gb SFP+ Autonegotiation

    Posted 10-24-2017 20:20
    On which device had u ran this command for xe and ge for interfaces?..i guess each device family has different norm for 10g SFP+ flavours..

  • 9.  RE: 10Gb SFP+ Autonegotiation

    Posted 10-25-2017 13:41

    I tested on a QFX5100 running 14.1X53-D26 and you can neither set no-auto nor delete auto-negotiation (as URL states) for 10GE or xe interfaces.  See output below:



    rmcgovern@WFD-QFX5100-48S-08# delete interfaces xe-0/0/0 ether-options auto-negotiation

    warning: statement not found


    So that URL link is inaccurate.  I have opened feedback for this situation.


    Just FYI.

  • 10.  RE: 10Gb SFP+ Autonegotiation

    Posted 10-25-2017 17:41

    If you don't have autonegotiation configured then of course you will get that error--just as if you tried to delete any other non existant configuration.


    Enable it, commit, then you can delete it.

  • 11.  RE: 10Gb SFP+ Autonegotiation

    Posted 10-25-2017 18:21
    All 10GE interfaces have auto-neg enabled by default per the 10GE standard. Auto-neg enabled is default setting.