I understand, what's the best approach to do this? Before upgrading firmware, disconnect all the cables with the switches turned off? then reconnect and apply upgrade?

It's not a dell server, i mean, the server could be the problem, but i cannot find any errors on my event viewer at all, i've changed nic, cables, eveything.. and it still happens.

Replacing the cables would be best, but even just disconnecting them and reconnecting them could help. It is still possible that it something with that exchange server as well. Is it a Dell server?

Yeah if it isn’t a Dell server we can just leave it alone for now. That plan sounds good for the cables and then updating the firmware.

Hi! thanks for the reply, you mean changin the HDMI stack cables for new ones?

Yes, i'm studying the procedure to update the firmware and the boot code, first i'll have to delete an older image to free some space from the switch and currently the option is disabled in the Webgui.

Hi taliska,

Have you tried reseat the stacking cables? It seems like it is causing the stack to fail. Here is the firmware update https://dell.to/3ggApic it includes the instructions on how to update. Let us know if you have any additional questions.

I couldn't ugprade the firmware and check the cables yet but..

Could this be related to RSTP? I found that i have besides the 5548 stack, another dell n2048p switch that connects to it.

Instead of RSTP is running PVRST with the same Priority that 5548 stack has. I know i have to lower down the priority of the stack to 4096, and change the n2048p to RSTP. 

But i have some doubts.. 

- Will this generate hiccups or shutdowns after i change the priority in the 5548 stack and establish RSTP in n2048p?
- How can i detect the designated ports on dell switches?
- How can i detect the BPDUID of each switch?

5548#
Root ID Priority 32768
Address 5c:26:0a:e3:51:69

n2048p#
CST Regional Root: 80:00:E4:F0:04:52:86:12
Regional Root Path Cost: 0
ROOT ID
Priority 32768
Address E4F0.0452.8612

So which one is acting as the root now?

No, i didn't reboot the switches or the server or upgraded the firmware yet. I'm still investigating.

Hi talishka,

Show spanning-tree detail should give you the information you need. I wouldn’t expect it to be a spanning tree issue. Have you rebooted the switches? Let us know if you have any additional questions.

Should be the 5548, if priority is the same the lower mac address takes priority.

I'm still trying to get some cables..i've got the part numbers, but i cannot find it on amazon.. btw. i'm located in Argentina.

part numbers

0.3M = 667T0
1M = PK5F4
3M = H25YT

Hi, the best way may be to contact sales. https://dell.to/3iWj549