Cisco 3850 Stack member number, priority, provisioning question

[xNightwingx]

I have an active stack of 3850s that's live in production.  I wasn't the person who set it up originally.  I need to add a switch to the stack, and I'm sure I'm way over thinking this.  They were all set to default priority. 

I want to be sure the member numbers don't change on the existing 3 switches in the stack, so I set the stack priorities of the members in order as they are now and set a provision for Stack member 4:

Mem#    Role            Priority     Current State

 1            Member      13            Ready

* 2            Active          15          Ready

 3            Standby       14            Ready

 4            Member       0             Provisioned

I also enabled auto-up upgrade so update the iOS on the new switch.

In reading the documentation, looks like I simply power off the new switch and loop it in and power it on?  Powering it on will cause the stack to reload and provision the new switch and hopefully the current members retain their numbers?  Anyone have any advice on this or words of caution?

[Flavio Miranda]

Yeah, exactly like this.  Usually a simple task, unless something realy exceptional occours. 

If I were you I´d upgrade the new switch before plug it, just to avoid any problem. 

[balaji.bandi]

In reading the documentation, looks like I simply power off the new switch and loop it in and power it on?  Powering it on will cause the stack to reload and provision the new switch and hopefully the current members retain their numbers?  Anyone have any advice on this or words of caution?

Sure if the global command configures to auto-upgrade, as soon as you connect the stack cable and power on, the upgrade process takes effect, make sure there is no active connection connected to that new switch.

it takes around 15min to 20min stack members to get auto-upgrade and reload.

yes, other members retain the same priority number that will not affect any config. when the new switch upgrades and reboots it joins as a member-only.

after all good, make sure you save the config (if required you can change the priority of the switch) from 0 to 12)

[Leo Laohoo]

---

@xNightwingx wrote:

Anyone have any advice on this or words of caution?

---

Regular (daily) monitor each CPU (3850 has 4 CPUs per switch) and memory utilization.

IF the a single CPU "hot spins" with >55%, get ready for it to pop.  

Memory utilization should be <43% and anything higher than that is not good.  

3850 requires regular "maintenance" (reboot to prevent crashing).