56128 / 5672 FEX Connection

[Rajagopal Sivaramakrishnan]

Can we connect the FEX to a QSFP port (40G) with 4x10G terminated on the FEX ? It doesnt seem to work.

56128  40G -----QSFP+------> 4x 10G ---> FEX ?

Please help me confirm this.
 

[Reza Sharifi]

Yes, you can.  You need a special brake out cable that has 40gig connector on one side and 4 10Gig LC connector on the other side to connect to FEXs via 10gig.

See figure-21 in this link:

http://www.cisco.com/c/dam/en/us/products/collateral/switches/nexus-9000-series-switches/white-paper-c11-729384.pdf

HTH

[Rajagopal Sivaramakrishnan]

Reza

yeah.. we have the cables.. but it doesnt work. The datasheet says these 40G's can be used for ethernet or FCoE. Doesnt work for FEX .. Is that the way it was designed ?

[Reza Sharifi]

Hi,

Can you provide the cable description and part number?

I have used many of these cables to connect 40Gig interfaces on Nexus 4004 to multiples FEXes (4).

This cable is specifically designed to connect 40Gig to 10Gig FEXes.

Let me know, if you want I can even find the part number for the cables I used.

HTH

[Rajagopal Sivaramakrishnan]

We use this standard breakout cables from Cisco.  One end of it goes to Nexus 56128 or Nexus 5672.. 4x10G's goes to the FEX's. The interfaces never come up if we use this cable. If we use a standard 10G twinax cable , everything works good

QSFP-4X10G-AOC5M

40GBASE Active Optical QSFP to 4SFP breakout Cable, 5m

[Reza Sharifi]

I use the cables made by Panduit

here is the part number for the cables I use and they all worked with no issues. Again mine was from Nexus 4004 to 2248 and 2232 FEXes

FX8HP5NLSQNF009 (PANDUIT OM3 8FIBER QSFP HARNESS)

Link:

http://www.panduit.com/wcs/Satellite?q=FX8HP5NLSQNF009&c=Page&childpagename=Panduit_Global%2FPage%2FSearch_Layout&cid=1345565623132&packedargs=locale%3Den_us&pagename=Search_Wrapper

HTH

[Rajagopal Sivaramakrishnan]

We tried various cables , but never works with 5600s.. 2248, 2348, etc.. nothing works..   need to check with Cisco TAC.

[network]

I'm trying to order cables to implement this same type of solution.  My connection is specified as:

Nexus 9504 (N9K-X9464PX)-- FET-40G --> 4x FET-10G --Nexus 2248TP-E

I have the FET-40G and the 4x FET-10Gs.  I've found documentation of the recommended FX8HP5NLSQNF009 8FIBER QSFP HARNESS.  The FET-10Gs clearly match the LC connectors on the harness.  The QSFP end of the fiber harness, as document, doesn't APPEAR to match visually with the FET-40G fiber connector.  I'm attaching a photo of the QSFP end of the harness and another photo of the FET-40G fiber interface to show the source of my confusion.  The photo of the QSFP interface of the harness shows a row of "holes" for the 12 fibers this connector supports.  (This harness doesn't use the center 4 fiber "holes".)  The FET-40G fiber interface has a row consisting of only 6 "holes" for possible fibers.

Does each of the four outer "holes" on the FET-40G actually interface to two fibers in the harness (with proper alignment)?