3850 stack member addition

[curtis03_2]

Hi

I have 3 member (WS-C3850-48P) stack currently running with sw image-cat3k_caa-universalk9  and sw version - 03.06.00E

I wish to add a fourth member to stack: -

• Will the stacking cables reach to the 4th switch ie from top switch to new bottom switch?
• Can i add the new switch even if the sw version is different to existing stack?
• If not, must i firstly manually upgrade stack to level of new switch, then join switch?
• What is the latest version for above model of switch please?    

thanks in advance

[Bilal Nawaz]

1) it depends on how long the stack cable is and how much space is between the top stack member and the most bottom stack member.

2) It's advisable to have the same software version running on the switch before you add it to the stack

3) depends, you can either upgrade or downgrade either - as long as they are on the same version

4) latest software is cat3k_caa-universalk9.SPA.03.07.01.E.152-3.E1.bin

Cisco's recommended software release for this platform is cat3k_caa-universalk9.SPA.03.03.05.SE.150-1.EZ5.bin

Hope this helps

Bilal

[curtis03_2]

thanks for your help Bilal

is the max number of members 4?

if so will the cables that come shipped with the new switch reach from the 1st to 4th?

thanks

[Bilal Nawaz]

I  think you can have up to 8 stacked members. I wouldnt take the risk with the stack cable, by one longer one in addition.

[curtis03_2]

cheers Bilal

[curtis03_2]

Bilal

my new switch is running 3.6.2a 

the existing stack is running 3.6.0e

do i need to downgrade the new device to 3.6.0e?

[Bilal Nawaz]

Yes, exactly, either that or you upgrade your existing stack to the same version (3.6.2a)

Hope it helps

Bilal

[curtis03_2]

Bilal

if i am running v3.6.0e will the software auto-upgrade function automatically detect and install the correct version on the new stack member?

saves me manually downgrading?

[Leo Laohoo]

Before you run the "software auto-upgrade" command, check the 3.6.0E Release Notes and confirm the new switch member will run on 3.6.0E firmware.  

Another thing, I would NOT recommend the continuous use of 3.6.0E firmware.  My recommendation is to use the newer 3.6.2aE due to bug fixes.

[curtis03_2]

Thanks Leo

I'm now confused. Surely when a new switch is purchased to add to an existing stack, the likelihood is it will be running a newer version than the stack???

This is my position - if I add the new switch running 3.6.2 to the stack I'll get a v-mismatch. Is the function of the auto-upgrade feature to ensure the new member is compatible ie running the same version as the stack members??

apologies for confusion!!

[Leo Laohoo]

Curtis, 

I am not sure what particular sub-model your new 3850 is going to be.  Check the Release Notes, it'll detail what minimum IOS version is required to support each specific sub-model of the 3850 series family of switches.  

I have never used this command because I haven't been to a situation that requires me to use this command.

[curtis03_2]

Downgraded new device (to match existing 3.6.0) before joining stack - all worked fine