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igano

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igano

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April 3rd, 2023 06:00

stack switch N1548

Hello

I'm looking for some advice please. I have a stack of 4x DELL switches - N1548 series. They are running firmware version 6.7.1.9

Last week, Unit 2 went into a strange mode where a "show interface status" will display N/A on every column (Speed, Neg, etc) except the Link State column where it showed "Detach". Not all hosts plugged into Unit 2 were affected, only a couple of them dropped off the network. Rebooting the switch fixed the problem, however today the same thing happened with Unit3. Again rebooting Unit 3 sort it out. 

Does anyone know what may be causing this strange behaviour? Are the switches slowly 'dying'?

Many thanks

  • - Muzz -

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    Posted April 12th, 2023 09:00

    igano,

    As to what caused it could be a number of things. the command "show switch stack-port diag" is often my first goto and see if there are any errors counters.
    if there are then it can be cable or stack-port itself. 
    There is also a chance that the "keep alive" from that switch was just not heard from the master switch so the member switch stepped forward in order to take over the role of master which kicked it out the stack. This can be caused by large CPU directed traffic hitting the "brain"CPU of the Master switch or just over saturation on the stack-port going to that member switch.

    Sadly the list can gon on and on. If it continues to cause an issue I'd say update the code as they do make corrections that affect stacking.

     

    I hope that helped

  • DELL-Charles R

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    Posted April 3rd, 2023 12:00

    Hello igano,

     

    Was any work or changes being made on the network around the time this started?

    It is a little behind on firmware. Could you bring the firmware up to date and test results?

    Firmware update: https://dell.to/3m47FBu

     

     

    DELL-Charles R

    Social Media and Communities Professional
    Dell Technologies | Enterprise Support Services
    #IWork4Dell

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  • igano

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    Posted April 6th, 2023 09:00

    Hi 

    No changes were made. Yes, I must bring the firmware up-to-date. I have been postponing it for a long time but I have to do it now. I was just wondering whether anyone else has experienced a similar behaviour. 

    Thank you

  • - Muzz -

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    Posted April 10th, 2023 15:00

    igano,

    Sounds like one or more of the stack members have left the stack.
    Use a console cable to connect to each switch in the stack. Use command "show switch" and you'll most likely see that there are switches that think they are the sole remaining member of the stack.

    On the switch that needs to re-join the existing stack:
    Disconnect power cable
    reseat stacking cable ate both ends
    re-connect power cable

    it should rejoin stack

  • igano

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    Posted April 12th, 2023 03:00

    Hi Muzz

    Thanks for your reply. I rebooted the switch and is back in the stack now. I was just wondering what caused this behaviour.  

    Thank you

  • igano

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    Posted April 13th, 2023 03:00

    Thank you for your time Muzz.