40GBASE-CR4 Passive Copper Cable, 1m

[kakintolu]

I connected a 40GBASE-CR4 Passive Copper Cable, 1m  cable  between 2 x C9500-24Y4C-E switches, but I don't get a connection. Is there something I am missing? 

[Leo Laohoo]

---

@kakintolu wrote:

I connected a 40GBASE-CR4 Passive Copper Cable, 1m  cable  between 2 x C9500-24Y4C-E switches, but I don't get a connection. Is there something I am missing? 

---

What firmware is the switch running on?

[kakintolu]

Switch#sh ver
Cisco IOS XE Software, Version 17.03.03
Cisco IOS Software [Amsterdam], Catalyst L3 Switch Software (CAT9K_IOSXE), Version 17.3.3, RELEASE SOFTWARE (fc7)

Switch#sh int status

Port Name Status Vlan Duplex Speed Type
Twe1/0/1 connected 1 full 25G SFP-25GBase-SR

Port Name Status Vlan Duplex Speed Type
Hu1/0/25 notconnect 1 full 40G unknown

[Leo Laohoo · Accepted solution]

Potentially a bug.  Either raise a TAC Case or upgrade to 17.3.5 or 17.6.2.

[marce1000]

 - Check logs of both devices when trying

 M.

[kakintolu]

Nothing in the logs -

Switch#sh int status

Port Name Status Vlan Duplex Speed Type
Twe1/0/1 connected 1 full 25G SFP-25GBase-SR

Port Name Status Vlan Duplex Speed Type
Hu1/0/25 notconnect 1 full 40G unknown

[marce1000]

          - Make sure the ports are set for autonegotation , 

 M.