[c-nsp] disabling GigE negotiation on NX-OS

Fri Apr 15 17:24:40 EDT 2011

dug through some kit -- found sfp-ge-s and a 62.5um cable.
same interfaces being used.

link came up for me.  again -- this is with n5000, not n5500, but i 
wouldn't think too great of a difference?

===============================
asr1002-1(config)#do sh run int gig 0/0/3
Building configuration...

Current configuration : 74 bytes
!
interface GigabitEthernet0/0/3
  no ip address
  no negotiation auto
end

asr1002-1(config)#do sh int gig 0/0/3
GigabitEthernet0/0/3 is up, line protocol is up
   Hardware is 4XGE-BUILT-IN, address is 588d.09ef.5103 (bia 588d.09ef.5103)
   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 force-up, media type is SX
   output flow-control is on, input flow-control is on
   ARP type: ARPA, ARP Timeout 04:00:00
   Last input 00:00:01, 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
      36 packets input, 4800 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, 36 multicast, 0 pause input
      0 packets output, 0 bytes, 0 underruns
      0 output errors, 0 collisions, 5 interface resets
      0 unknown protocol drops
      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

---------------------------------

n5020-1# sh run int e1/1

!Command: show running-config interface Ethernet1/1
!Time: Fri Apr 15 21:16:15 2011

version 4.2(1)N2(1)

interface Ethernet1/1
   speed 1000

n5020-1# sh int e 1/1
Ethernet1/1 is up
   Hardware: 1000/10000 Ethernet, address: 0005.73a1.6508 (bia 
0005.73a1.6508)
   MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
      reliability 255/255, txload 1/255, rxload 1/255
   Encapsulation ARPA
   Port mode is access
   full-duplex, 1000 Mb/s, media type is 1/10g
   Beacon is turned off
   Input flow-control is off, output flow-control is off
   Rate mode is dedicated
   Switchport monitor is off
   Last link flapped 00:03:47
   Last clearing of "show interface" counters 00:33:26
   30 seconds input rate 0 bits/sec, 0 packets/sec
   30 seconds output rate 184 bits/sec, 0 packets/sec
   Load-Interval #2: 5 minute (300 seconds)
     input rate 0 bps, 0 pps; output rate 96 bps, 0 pps
   RX
     0 unicast packets  1 multicast packets  0 broadcast packets
     1 input packets  81 bytes
     0 jumbo packets  0 storm suppression packets
     0 runts  0 giants  0 CRC  0 no buffer
     0 input error  0 short frame  0 overrun   0 underrun  0 ignored
     0 watchdog  0 bad etype drop  0 bad proto drop  0 if down drop
     0 input with dribble  0 input discard
     0 Rx pause
   TX
     0 unicast packets  218 multicast packets  0 broadcast packets
     218 output packets  32576 bytes
     0 jumbo packets
     0 output errors  0 collision  0 deferred  0 late collision
     0 lost carrier  0 no carrier  0 babble
     0 Tx pause
   2 interface resets
===============================

i've used this article in the past[0].  while dated -- it seems to have 
some good information.  it doesn't appear that speed nonegotiate is 
accepted under the 4.2 code on n7k -- so i'd assume similar parity in 
4.2 on n5k platform.

i tried to pull of the optic information from my n5k -- but its not 
coming out clean.  however, when i use this transceiver in n7k, i get 
the following output

================================
n7k-1# sh int e 1/25 trans
Ethernet1/25
     transceiver is present
     type is 1000base-SX
     name is CISCO-FINISAR
     part number is FTLF8519P2BNL-C6
     revision is B
     serial number is FNS143907J7
     nominal bitrate is 1300 MBit/sec
     cisco id is --
     cisco extended id number is 4
==================================

when i try to configure speed on n7k running 5.1(3) code, i get the 
following options (which may lend more insight into why this works

===================================
n7k-1(config)# int e 1/25
n7k-1(config-if)# speed ?
   10     10Mb/s
   100    100Mb/s
   1000   1Gb/s
   10000  10Gb/s
   auto   Auto negotiate speed
====================================

not sure if hard-setting the speed and negotiation are mutually 
exclusive -- but i'm just passing along what i'm seeing.

q.

[0]http://www.netcraftsmen.net/component/content/article/69-data-center/807-migrating-to-nexus-7000-from-catalyst-6500-and-4500-switches.html

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On 04/15/2011 02:01 PM, Gert Doering wrote:
> Hi,
>
> On Fri, Apr 15, 2011 at 01:44:03PM -0700, quinn snyder wrote:
>> testing in my lab now -- simple back to back copper over glc-t between
>> n5020 running 4.2(1)n2(1) and asr1002 running 3.1.0s
>
> Thanks for testing, but I'm afraid this won't bring new information -
> copper GE and fiber GE is significantly different here, and as far as
> I understand, there is no way to run GE copper without negotiation
> (both ends need to agree who is PHY master and slave, and sort out the
> wire pairs).
>
> So it might disable negotiation of flow control and such, and might
> show the link as "always up", but the PHY will still negotiate.
>
> [..]
>> interface Ethernet1/1
>>    speed 1000
>
> We (the customer) had that, but that wasn't sufficient.  But if that
> indeed disables link negotiation for fiber SFPs, we had some other
> problem...
>
> In any case: thanks for the suggestions so far!
>
> gert
>