25G transceiver and DAC recognized but no link

[arnaud-l]

Hi all, 

New owner of a 93180YC-EX here. It is running  7.0(3)I4(7).

I've tried ipolex 25G SFP28 DAC cables, seen as SFP-H25GB-CU1M as per the below:

sh int eth1/31 transceiver detail
Ethernet1/31
    transceiver is present
    type is SFP-H25GB-CU1M
    name is OEM
    part number is SFP-H25G-CU1M
    revision is 00
    serial number is CSC250108540073
    nominal bitrate is 25500 MBit/sec
    Link length supported for copper is 1 m
    cisco id is 3
    cisco extended id number is 4

DOM is not supported

Sadly, link remains down, whatever I try, including using the command "service unsupported-transceiver".

Any idea why?

Trying to solve the issue, I've also used the following combination: 10G SFP - optical patch cable - 25G SFP.

When having the following configuration: Server with 25G SFP - patch cable - 10G SFP in switch, it works, link is up at 10G, but when having the Server with 10G SFP - patch cable - 25G SFP in switch, it doesn't work and transceiver details are the following:

sh int eth1/30 transceiver detail
Ethernet1/30
    transceiver is present
    type is SFP-H25GB-SR10M
    name is CISCO-FINISAR
    part number is AZS85-S28-M1/GR
    revision is B
    serial number is CSG251P40142
    nominal bitrate is 25500 MBit/sec
    Link length supported for copper is 10 m
    Link length supported for 50/125um OM3 fiber is 70 m
    cisco id is 3
    cisco extended id number is 4
    cisco part number is 10-3227-01
    cisco product id is SFP-25G-SR-S

           SFP Detail Diagnostics Information (internal calibration)
  ----------------------------------------------------------------------------
                Current              Alarms                  Warnings
                Measurement     High        Low         High          Low
  ----------------------------------------------------------------------------
  Temperature   37.22 C        95.00 C    -10.00 C     75.00 C       -5.00 C
  Voltage        3.27 V         3.59 V      3.00 V      3.50 V        3.09 V
  Current        7.18 mA       12.00 mA     2.00 mA    10.00 mA       4.00 mA
  Tx Power       1.19 dBm       3.39 dBm   -8.01 dBm    2.39 dBm     -7.01 dBm
  Rx Power       0.56 dBm       3.39 dBm  -14.08 dBm    2.39 dBm    -13.01 dBm
  Transmit Fault Count = 0
  ----------------------------------------------------------------------------
  Note: ++  high-alarm; +  high-warning; --  low-alarm; -  low-warning

Both Eth1/30 and Eth1/31 are configured the same way.

What am I doing wrong here?

Any help is appreciated.

[M02@rt37]

Hello @arnaud-l 

Server with 10G SFP - patch cable - 25G SFP in switch, it doesn't work ?

--not the same speed on each end ??

[arnaud-l]

Correct, it doesn't work, while switching the transceivers, having the 10G in the switch works, at 10G.