New switch take over active and override in stacking

[MrBeginner]

Hi,

I just want to know about stacking. I am configured two switch 9200L series as stack.Active switch is priority 15 and standby is priority 13. I noticed that standby switch got some issue, so i swap with new swtich . I configured priority 11 on new switch. I didn't add any configuration on new switch and swap with old standby switch.I power off standby switch,pull out stack cable from standby switch and put on new standby switch.Then i power on the new standby switch. When i trun on the power to new standby switch,the all of LED status of active switch are changed from green to off.And then the standby default configuration are override to existing active switch configuration.

So let me know what kind of wrong configuration can override to active switch ?

To avoid accident ,what is the best practise for standby switch swap process ?

[balaji.bandi]

9200#switch <number> priority 11  ( saved the config)

that switch should not become until some process you doing wrong.

post below information :

show version from both

show run from active

show switch from active

connect console to standby post complete boot (if you can ssh to active same time and capture the logs) and post here.

for reference :

https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-9200-series-switches/nb-06-stackwise-architecture-cte-en.html

[MrBeginner]

Hi,

As per your comment, if we configure  switch no and lower priority number in replacement, it will not override to existing switch ?

[balaji.bandi]

yes, correct. if you do not save the config, it tries to participate in the stack master election process, then who ever wins will be the master.

if you deliberately setup the number and priority and save the config, then it will join the exiting master switch.

i am sure you see this on the console of the device election process.