Flyfish712,

From your description the issue looks to be cabling based, I wouldstart with looking at the stacking cables.

Let me know what you see.

Thanks.

Did you means my stack cable issue and I need to change cable? 

Can I check my cable from switch command?

Thank you.

I just tried change cable but the issue still exists, I found Tw1/0/2 and Tw3/0/1 link light is out.

I tried running: "stack-port twentygigabitethernet 1/0/2 shutdown" twice and "show switch stack-ports" , but the port link status also shutdown.

Hi @flyfish712,

Have you tried "stack-port twentygigabitethernet 1/0/2 no shutdown"? 

In normal circumstances, you need not do any configuration on stacking ports, but in this case, try using the command above to try enable the port. 

Could you confirm your cabling topology, would that be:

● The bottom mini-SAS port on Unit 1 is connected to the top mini-SAS port on Unit 2.
● The bottom mini-SAS port on Unit 2 is connected to the top mini-SAS port on Unit 3.
● The bottom mini-SAS port on Unit 3 is connected to the top mini-SAS port on Unit 1.

https://dell.to/3tRYC7r

I would suspect that N3024P is not supported in the stacking, as it's a POE switch which needs a deliverance of 62W power, which N3048 is unable to support. Could you try both N3048 only and check if the stacking works. 

Attached reference for stacking switch on power on sequence: https://dell.to/3OtiaXy

Hello Joey,

Thanks for your replied, the command  "stack-port twentygigabitethernet 1/0/2 no shutdown" is not work in my N3048 Switch:

I just checked the cable connection is ok.

Our company IT room has deployed N3024P and N3048 switches stack, it works, so I think it's ok.

Hello @flyfish712,

If you already checked the cables and they are ok and you were not able to use the suggested command I should advice you to check the configuration. Maybe someting in the configuration is preventing this ports to go up.

Regards.

Hello Diego Lopez,

I have contacted local Dell support via email and waiting for them answer, also will give you feedback when the issue resolved.

Thank you so much.