Physically re-ording switches in a stack

[DHGmem]

During the hardware replacement of a 5 member switch stack, I realized after cabling two of the five switches that the switches were configured out of order. I had prepared them in order and after racking them I verified their order with serial numbers, but somewhere along the line I got them out of order. Its currently like so...

Switch 1

Switch 3

Switch 5

Switch 4

Switch 2

Switch 1 is cabled and good to go.

Switch 3 (which during the time i thought was Switch 2), was cabled and i removed the old Switch 2 from the rack. When i realized the switches were out of order, in a panic (a small change control window) I removed the cables and placed them in the bottom switch, Switch 2.

Switch 1 - cabled

Switch 3 - empty

Switch 5 - empty

Switch 4 - empty

Switch 2 - cabled.

Switches 3-5 are still running on the old switch stack in parallel with the new 9300 stack.

Am i able to remove switches 3, 5 and 4 from the rack and place them in the proper positions without taking out Switches 1 and 2?

The Stackwise cables are in a ring topology, if Switch 3 is removed from the second slot and re-enters the stack in position three, will there be an issue?

I've looked through the Whitepapers and couldn't draw a proper conclusion. I was hoping someone more experienced and perhaps has made a similar boo-boo would help a new networking professional out.

Thanks.

[balaji.bandi]

Personally i would advise go with change window with small maintennace window. change the number priority and cable stuff make sure it corrected.

not sure some confusion in terms of your details explain (or i miss understating)  so i suggest here is the step by step

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9300/hardware/install/b_c9300_hig/b_c9300_hig_chapter_010.html

https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-9300-series-switches/white-paper-c11-741468.html

Note : when you re-order the switch, the number will change, and any Physical connecte device port numbers change, this is not going to effect, but if the VLAN are different they do change, make sure port description also change in case monitoring.

[Seb Rupik]

Hi there,

"Am i able to remove switches 3, 5 and 4 from the rack and place them in the proper positions without taking out Switches 1 and 2?"

- The short answer is yes. I would ensure that Switch1 and Switch2 are connect by both StackWise cables to ensure the stack run isn't broken when you move the switch. I suggest you fully remove Switches3,4,5 and just slide Switch2 up the rack, providing you have enough length in the patch cables you will be able to do this without an outage...we've all been there!

"The Stackwise cables are in a ring topology, if Switch 3 is removed from the second slot and re-enters the stack in position three, will there be an issue?"

- I'm a bit confused, you say you have a ring topology, but I assume you mean to say you have two separate rings for the old (switches3,4,5) and new (Switches1,2).

I would physically move Switch2 to 'position 2', then break up the old stack and physically move the switches into their correct rack positions. Cable up the stackwise cables, ensure that the connection between Switch1 and Switch2 remains undisturbed as you will be running with a degraded stackring during this re-cabling. Once the stack ring is reconnected into a single loop, start powering on switches3,4,5.

cheers,

Seb.

[DHGmem]

The five new 9300 are already stacked, connected to each other with Stackwise cables. To move the switches physically, i would need to remove the stackwise cables from switches 3, 4 and 5 - then plug them back in different order. I just want to make sure that if i unplug/plug the Stackwise cables, its not going to mess with the ordering of switches 1 and 2 once their plugged back in.

The ordering of the switches is based on the configured priority of the switches, identified by Serial Numbers as far as i can tell.

Switch 3 is currently plugged into Switch 1 and 5 - if its removed by physically reordering the stack and boots back up but is now connected via Stackwise to Switch 2 and 4, what kind of impact will that have?

[DHGmem]

Update...

Re-racking the switches in a different order was not a problem.

I removed all the switches and provisioned them back into the stack one at a time. The switch order was based on serial number so the positioning of the Stackwise cables didn't affect the configuration, and there was no downtime.

[balaji.bandi]

Glad all good, thank you for the feedback and outcome.