MS390 Uplink using 2x40G module

[CBINETWORK]

I have these brand new MS390 switches that I want to uplink to the Distribution switches. I have installed the 2x40G QSPF+ modules and they work when connecting 2 MS390's together but when I connec them to the MS450 that ports stay in the disconnected state. 

The config on both ends is default. I have a 40G QSFP+ cable and they both indicate in the syslog that the port is up but stays in a disconnected state.

On the MS450 syslog shows the cables is connected, the port is up and it is running at 10G

On the MS390 syslog shows no change in status.

I have multiple MS390's and MS450's and have tried on all of them and get the same result. There must be something I am missing with these.

Cables uses are MA-CBL-40G-3M

I have the MS450's stacked together

I have 3 sets of MS390 is 2 pair stacks. The uplink issue exists with or without the stacking on all switches. I can connect to the MS390 copper ports and access the switches so I know they do work...sort of!

[Tore]

Please check your SFP and fiber cables.

What do you use?

br,

Tore

[CBINETWORK]

The cables that I am using are MA-CBL-40G going from the MA-MOD-2X40G to a MS450. The Meraki compatibility matrix says these cables will not work for the MS390, however, they work from MS390 to MS390.

[Tore]

MA-CBL-40G is a stacking cable and should be used to stack switches.

The MS450 needs these stacking cables: MA-CBL-100G (MA-CBL-40 i not supported)

The MS390 needs these: MA-CBL-120G

In the uplink module ports of the MS390 and the ports on the 450 you would need the approriate SFPs for the fiber cables you need. Typically either SR/LR or MM/SM