nexus 3000 10G interface 'Link not connected'

[larrycotton]

Hi

I have a 10G nexus 3524x:

switch# show version
Cisco Nexus Operating System (NX-OS) Software
TAC support: http://www.cisco.com/tac
Documents: http://www.cisco.com/en/US/products/ps9372/tsd_products_support_series_home.html
Copyright (c) 2002-2016, Cisco Systems, Inc. All rights reserved.
The copyrights to certain works contained herein are owned by
other third parties and are used and distributed under license.
Some parts of this software are covered under the GNU Public
License. A copy of the license is available at
http://www.gnu.org/licenses/gpl.html.

Software
  BIOS:      version 2.0.10
  loader:    version N/A
  kickstart: version 6.0(2)A7(2)
  system:    version 6.0(2)A7(2)
  Power Sequencer Firmware:
             Module 1: version v2.1
  BIOS compile time:       03/06/2018
  kickstart image file is: bootflash:///n3500-uk9-kickstart.6.0.2.A7.2.bin
  kickstart compile time:  2/18/2016 8:00:00 [02/18/2016 17:46:27]
  system image file is:    bootflash:///n3500-uk9.6.0.2.A7.2.bin
  system compile time:     2/18/2016 8:00:00 [02/18/2016 18:10:06]


Hardware
  cisco Nexus 3548 Chassis ("48x10GE Supervisor")
  Intel(R) Pentium(R) CPU  @ 2.00GHz
 with 3794056 kB of memory.
  Processor Board ID FOC221012ZM

  Device name: switch
  bootflash:    3932160 kB

Kernel uptime is 5 day(s), 0 hour(s), 8 minute(s), 14 second(s)

Last reset
  Reason: Unknown
  System version: 6.0(2)A7(2)
  Service:

plugin
  Core Plugin, Ethernet Plugin
switch#

When I try to connect to one of my devices the interface remains down reporting 'Link not connected':

switch# sh int Eth1/5 br

--------------------------------------------------------------------------------
Ethernet      VLAN   Type Mode   Status  Reason                   Speed     Port
Interface                                                                   Ch #
--------------------------------------------------------------------------------
Eth1/5        100     eth  access down    Link not connected          10G(D) --
switch#

Transceiver information:

switch# sh int Eth1/5 transceiver detail
Ethernet1/5
    transceiver is present
    type is SFP-H10GB-CU3M
    name is Molex Inc.
    part number is 74752-1301
    revision is
    serial number is 614440271
    nominal bitrate is 12000 MBit/sec
    Link length supported for copper is 3 m
    cisco id is 3
    cisco extended id number is 4

DOM is not supported

switch#

If I simply loop the connection back to another port on the switch the link status goes to 'up', so it recognises itself.

Does any one know what it is that causes the switch to determine the link is connected and activate the interface on a 10G link ?
Is there some specific configuration I need to do before the link can be activated ?
Anyone have any ideas on how I can troubleshoot this ?

[Reza Sharifi]

Hi,

What device is port e1/5 connected to?

Does it support 10G?

HTH

[larrycotton]

It's a custom reference board we use at work. Yes it supports 10G.
However I do not know anything about the interface specification, so do not know what signal the switch is expecting to identify an active link (and then whether the device is actually giving that signal - which hopefully I can check when I know what it should be).

[larrycotton · Accepted solution]

Well I did a little more digging and, to answer my own question, the device I am using to connect to the switch was using cl72 handshake protocol and it seems the switch is not using this (at least be default). When I disable cl72 on my device the link comes up successfully. Using xfi also works fine.

I have not yet been able to work out whether these protocols are configurable on the switch, or even how to tell which ones are enabled/disabled on the interface.

[Vl@d@Ni]

Hi,

can you share with us how did you disable cl72 protocol ?

[Mosasa]

lol don't you love it when people find solutions but don't even bother to share the said solution??