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:
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?
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.
Loopback is a diag test to velidate HW.
Sounds like you doing testing, not prod.
put int in loopback and run both internal & line.
from both ends of NX boxes:!
you will see lines come up in debug
look for errors
if you can't pinpoint errors
try loopback internal