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How to pull one switch out of stack?

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  • 1.  How to pull one switch out of stack?

    Posted 02-05-2020 06:08

    We have a stack of three switches

    1. Member 0, EX4500 - routing engine
    2. Member 1, EX4200 - line card
    3. Member 2, EX4200 - backup

    We want to pull the EX4500 out of the stack which means one of the EX4200s becomes the routing engine. I am guessing our config will need to change since right now one EX4200 has interfaces like ge-1/0/0 and the other EX4200 has interfaces like ge-2/0/0. I am thinking that yanking out the EX4500 which is member 0 will end up renumbering the two EX4200s left so interface names need to change.



  • 2.  RE: How to pull one switch out of stack?

     
    Posted 02-05-2020 06:34

    FPC numbering is tied to device serial number. If you remove Member 0, member 2 will become the new RE based on your output. Interface numbers remain unchanged, and ge-0-* interfaces will all show as down. If you don't plan to replace the EX4500 then you don't need to do anything further except maybe delete member 0 from the virtual-chassis section (and all ge-0-* interfaces) if it is configured using the preprovisioned method. If you do plan to replace the switch and you are using preprovisioning you just need to change the config to reflect the new serial number. If you are not using preprovisioning you should issue 'request virtual-chassis recycle member-id 0' before adding it so that the replacement switch gets member 0. Otherwise it will become member 3 and you will need to change all of your ge-0-* to ge-3-*.



  • 3.  RE: How to pull one switch out of stack?

     
    Posted 02-05-2020 06:38

    Hello Henderson,

     

    if this should work as smooth as possible with very low, please make sure that you have features like GRES and NSR/NSB configured. Then you can change the mastership with "request chassis routing-engine master [release|switch]". After this, you can perform "request system halt member 0". Then you can pull out the EX4500.

     

    The config is not needed to change. The interfaces stay like ge-1/0/0 or ge-2/0/0 as they are, there is no technical need to renumber one of the members to e.g. ge-0/0/0.

     

    Do not forget to perform "request virtual-chassis recycle member-id 0" after the EX4500 has been pulled out, to delete the VC entry for this device.



  • 4.  RE: How to pull one switch out of stack?

     
    Posted 02-05-2020 07:05

    Hi Henderson,

     

    Just power off the EX4500 device and recycle the member-id if it is nonpreprovisioned VC. If you are moving any cables from member 0 to other swithes, you need to change the configuration. 

     

    Few things to remember, configure no-split-detection as it is going to be a two member VC. Another thing, removing EX4500 is going to change the VC from mixed VC to non-mixed VC which might need to to disable mixed mode and reboot of all the nodes.

     

    request virtual-chassis mode mixed disable all-members
    request system reboot all-members

     

    Thanks and Regards,

    Pradeep Kumar M



  • 5.  RE: How to pull one switch out of stack?

     
    Posted 02-05-2020 13:01

    HI Hendeson D

     

    Greetings, here is the official documentation for this procedure in case it is needed.

     

    ON THIS PAGE

     

     

    https://www.juniper.net/documentation/en_US/junos/topics/task/installation/virtual-chassis-ex4200-member-replacing-cli.html 

     

    Regards,
    Lil Dexx JNCIE-ENT#863

     

    If this solves your problem, please mark this post as "Accepted Solution" so we can help others too \:)/



  • 6.  RE: How to pull one switch out of stack?
    Best Answer

    Posted 02-06-2020 11:37

    Hi HendersonD,

     

    The procedure you mentioned is correct.

    Make sure you have GRES/NSR/NSB and set system commit synchronize enabled.
    Do master RE of EX4500(0) to EX4200(3).
    Once EX4200 is new Master.
    You can now remove the EX4500 and delete the VCP ports first via cli.

    later change the configuration of the virtual chassis so it can be member 3 and 2 (you can leave it like that or renumber it).
    Later remove the configuration of member 0.

    Note: the VC will stay in mixed mode, until you reboot the entire stack to disable the mixed mode feature (having the member in mixed shouldn't cause any harm)

     

    If this solves your problem, please mark this post as "Accepted Solution".

    If you think that my answer was helpful, please spend some Kudos.

     

    Thank you, 

    Franky