40Gb breakout interface numbering consistency?

[ayee]

Recently I configured a 40Gb breakout link between two switches, on one side a Nexus 7706 w/a N77-M324FQ-25L blade, and on the other side, a Nexus 9336C-FX2 connected via a WSP-Q40GLR4L optic.  This worked out nice and tidy with the four interfaces on one side matching the four on the other one for one.

I then tried swapping the optics with a QSFP-40G-SR-BD.  The interfaces on both side showed link with breakouts, but the port numbering was now shifted.  Instead of 1-to-1 it was now off by two like so:

 N7706                  N9336

eth1/9/1       -      eth1/9/3

eth1/9/2       -      eth1/9/4

eth1/9/3       -      eth1/9/1

eth1/9/4       -      eth1/9/2

I've swapped optics multiple times and even between switches, and aside from one combination where the breakouts interfaces were shifted by three instead of two, they have been consistently offset like this.  Is there anyway to change this to make them consistent?  Am I doing something wrong?

[mohAmed khAdr]

That's really odd.

Couple of things to try:

1) try loopback z quad from NX 7k side and see what errors you get.

2) try SM drop. MMF sometimes can cause a flap.

HTH

mohamed

[dit network]

Not sure what you mean with option 1, but option 2 works with every optic I've tried on SM.  LR4L and WDM.

[mohAmed khAdr]

Loopback is a diag test to velidate HW.

Sounds like you doing testing, not prod.

enable debugging

put int in loopback and run both internal & line.

from both ends of NX boxes:!

conf 

int exx/xx/xx 

loopback line

you will see lines come up in debug 

look for errors

!

if you can't pinpoint errors

try loopback internal

!

HTH