Symptom

While both top and bottom ports are up, if some down event occurs on the bottom port and the bottom port has a copper SFP (admin down or otherwise), the corresponding top port will also go down with it. It will show as the "link down not-connected" behavior for top port Ethernet1/15 is down (notconnect) admin state is up, Dedicated Interface This occurs even though the QSFP is still inserted and was otherwise previously up and functional.

Conditions

This issue occurs with a 93180LC-EX switch running the Cisco NX-OS 13.0(2n) release. Both the bottom and top port in a pair (ex 1/1 and 1/2, 1/3 and 1/4) are up, however the bottom port in a given pair is using some copper SFP such as: type is QSFP-40G-CR4 cisco product id is QSFP-H40G-CUXM The top ports SFP can be copper or fibre. The main issue is with the bottom port having a copper SFP.

Workaround

Utilize only odd numbered (top) ports. This will ensure no unexpected port down events occur if only copper SFPs are available. Or Use Fibre QSFPs in the even numbered (bottom) ports.

Further Problem Description