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Author Topic: ERS 55x0 - Add a unit in the middle of stack  (Read 1070 times)

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Offline Alessan

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ERS 55x0 - Add a unit in the middle of stack
« on: February 08, 2016, 03:39:05 PM »
Is safe add a new unit on the middel of an stack? (rack space problems)

for example, if i add an unit between unit 4 and 5...unit 5 will be converted to 6 whithout loss port configuration? (vlans, etc).

thanks in advance.


Offline Johan Witters

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    • BKM Networks
Re: ERS 55x0 - Add a unit in the middle of stack
« Reply #1 on: February 09, 2016, 04:05:51 AM »
Hi Alessan,

you can add a unit in the middle of the stack without any problems, but keep these in mind:
1) mount the unit in the rack, eg. at position 5
2) disconnect the 2 stacking cables and connect them to the new unit
5) power-on the new switch, give it some time to be taken up into the stack. I will have to sync software and configuration, so it might reboot a few times
6) the new unit is now in the stack, but with default port assignment (all ports in vlan 1), so correct the configuration. Configuration of the other units will not have changed. Also note that the new unit will not have taken the "correct" number within the stack, but next available unit. So if you add a new unit on position 3 within a stack of six, it will receive unit #7, not 3. Also in EDM/JDM it will be shown as the unit at the bottom
7) to correct the numbering, you can run the stack renumber command to re-assign the stack unit numbers, but keep in mind that the stack needs to be rebooted to correct the numbering.

Kind regards,

Johan Witters

Network Engineer
BKM NV

Offline Alessan

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Re: ERS 55x0 - Add a unit in the middle of stack
« Reply #2 on: February 10, 2016, 12:30:04 AM »
One question more,

 Any problem exchanging on a stack a 5510 24 ports switch by a 5510 48 ports? Is the 24 first ports config copied?

Thanks a lot,


Offline Johan Witters

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    • BKM Networks
Re: ERS 55x0 - Add a unit in the middle of stack
« Reply #3 on: February 10, 2016, 05:17:59 PM »
No, unless something changed in a recent release the stack will revert those ports back to default settings.

When you replace a unit 1-1 it puts the config of the original unit onto the new one. But if you change it with a different model, it does not as it is not the same configuration. Also, if I'm not mistaken the new unit will get a new unit number as well and you need to renumber the stack afterwards...

I suggest the following:
1) take a backup of the current configuration
2) power down the original unit, replace with then new one and boot it
3) wait untill it is fully loaded in the stack and check the unit number (show stack-info)
4) reconfigure the new unit (you can copy/paste the configuration of the old unit, just change the unit number and port numbers if needed)
5) if the swapped unit received a different unit number, renumber the stack. Keep in mind it will reboot the stack during the renumbering.
Kind regards,

Johan Witters

Network Engineer
BKM NV