Cisco QSFP-40G-SR-BD Breakout

[MonEntropy]

I want to configure a 10G uplink from a C9300-48U-E (stack) with the C9300-NM-8X (8x10Gb module) to the QSFP port on a Nexus N9K-C9348GC-FXP (40G). I have the QSFP-40G-SR-BD plugged in and did the module breakout, but I don't see where I can tie the 10g uplink to one of the 4 breakout interfaces from the Nexus.

Is this even a supported scenario? Or will I need to go with QSFP module for the Catalyst?

[MHM Cisco World · Accepted solution]

https://www.cisco.com/c/en/us/products/collateral/interfaces-modules/transceiver-modules/whitepaper-c11-744077.html

Check this guide. 

[Leo Laohoo]

Question:  Why not get a C9300-NM-2Q instead?

[MonEntropy]

Yes - that was the first route, it's on order, but the lead time on the part is beyond the requirements.

[Reza Sharifi]

Once you convert a 40Gig to 4 10Gig, there is naming convention depending on the module you are using. Should be:

Ethernet slot/front panel port/breakout port

see page 9 in this document:

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/93x/interfaces/configuration/guide/b-cisco-nexus-9000-nx-os-interfaces-configuration-guide-93x.pdf

Ethernet //. For example, per-port level breakout ports can be identified as Ethernet 1/2/1, Ethernet 1/2/2, Ethernet 1/2/3, and Ethernet 1/2/4.

[MonEntropy]

That is true - While it does break it out to the 4 interfaces on the Nexus side and I can see them all (and I enabled all of them just to make sure that something had light going through) - I still wasn't able to get a connection with the SFP interface on the Catalyst. I subsequently tried it with the quad breakout AOC cable and that worked like a charm.

Could it be that the QSFP (that has LC fiber connection) to 10G single SFP just isn't an option? 

[MonEntropy]

And from the link provided earlier by MHM Cisco World, "Also, some transceivers like the QSFP-100G-SR-BD and QSFP-40G-SR-BD don’t have breakout capability..." So... I guess that's my answer.

[Reza Sharifi]

Could it be that the QSFP (that has LC fiber connection) to 10G single SFP just isn't an option? 

Could be, because BD is a Cisco propriety optic and used to be available on the Nexus platforms only, but now it can work on Catalyst as well.

Good Luck!