93180 + FEX Cabling options / limitations?

[Nathan Farrar]

I'm putting together a relatively small data center and I'm a bit confused on all of the options for the 9K / 2K FEX integrations. 

I have 2 93180YC-EX switches at the head and will be using 2348TQ FEXs

I am going to have three cabinets and will put together two options:

Option 1 : Single 2K in each cabinet. Servers will uplink with 10GbE port channels

Option 2 : Dual 2K in each cabinet. Servers will use single link to each 2K and form a vPC. The 2Ks will go back to to one of the 9K parent switches.

For either option, I'd like to get 40GbE back to the 9K's. What are my options? I'd like to use twinax if possible but I'm not sure if it is with the QSFP ports. I have found the QSFP breakout cables but I don't think that'll do. The FEXs have 6 QSFP ports on them, I figure I can use one of these to each 2K. I'm also concerned about length since it looks like the longest run will be just over 30 feet.

Thanks!

[Reza Sharifi]

For this type of connectivity, the easiest part to use is the Cisco Bi-Di (40Gig) optic. You simply put a Bi-Di optic on each device and run a cable between them or multiple.  The cable can be multimode LC/LC. Also, Bi-Di is so much cheaper compare to regular QSFP and you don't have to worry about the distance if it is more than 30 feet.

https://www.cisco.com/c/en/us/products/collateral/interfaces-modules/40-gigabit-modules/white-paper-c11-732764.html

https://www.cisco.com/c/en/us/products/collateral/interfaces-modules/transceiver-modules/datasheet-c78-736282.html

HTH

[Nathan Farrar]

Howabout something like this?

https://www.fs.com/products/30915.html?currency=USD&paid=google_shopping&gclid=EAIaIQobChMIk66Wsoek2QIVlYnICh3hpgzBEAYYASABEgJj9_D_BwE

And from the looks of it, there are two ports on each 2K that can be used to link up to the parent? Or can you use any port. I say this because there are two ports that have yellow highlight around them, I'm just assuming here.

Thanks!

[Reza Sharifi · Accepted solution]

Yes, this works too. The length is 49 ft which is long enough for you. So, you should be good to go.

HTH

[Reza Sharifi]

You can use any of the 6 ports.  I usually use the first 2 with the yellow highlight around them if I need just 2 40Gig uplinks.

HTH

Good Luck!

[Nathan Farrar]

Can you use the QSFP ports on the 2k for hosts? I'd like to use a QSFP breakout cable to go to 4 10GbE ports on servers if possible. It will allow me to use the RJ45 2K and save on transceivers.