Adding Replacement 3850 to Stack

[david.klein]

I have a stack of 4 3850 switches 

Switch# Role Mac Address Priority Version State
------------------------------------------------------------
1 Standby 00eb.d5e2.7880 15 V05 Ready
*2 Active 188b.4583.1480 14 V05 Ready
3 Member b090.7ed4.a400 13 V06 Ready
4 Member ccd8.c1b1.7e00 12 V03 Ready

I found out that switch 3 is bad and not handing out an POE.  I have received my replacement switch and am going to remove old switch and put in the new switch.  New switch also has a newer IOS version then the other 3 switches.  What I usually do is boot up new switch, renumber to the switch it will be.  In this case I did renumber switch 1 to 3, I changed the priority to 13 instead of 1 and turned off vtp.  I also put command in for software auto-upgrade enable.

My question is this.  Is that all I need to do?  Do I need to copy old interface config on to the new switch or will that all copy over when I put switch in.  Also after I replace switch, will all other switches auto upgrade and reboot automatically to the new IOS or can I reload one switch at a time and when it reboots it will auto upgrade and reboot, probably a couple reboots?

[balaji.bandi]

thats all you need.

i suggest to upgrade the IOS offline rather autoupgrade.

1. upgrade what you have current with License level

2. switch number

3. priorty

Turn off the device - rack it, connect the stack cables and power on check post checks.

Note : worth take the current stack running config out of the box more conscious.

[david.klein]

So would I go to one of the current stacked switches and unplug one of the stacking cables to get it offline do the IOS upgrade, then proceed to do the same on each switch?  until they are all upgraded to the same IOS as the one I'm adding, then reconnect the stacking cables after all are up to the correct IOS?

[david.klein]

If I do just plug in new switch to the stack will others automatically update and reboot?

[Leo Laohoo]

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@david.klein wrote:

I found out that switch 3 is bad and not handing out an POE. 

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Have you tried COLD REBOOT (pull out all the power cables) of the entire stack?

If you did and the COLD REBOOT fixed the issue, I know exactly what this problem is:  CSCvj76259 & CSCvd46008

[david.klein]

I ended up replacing the switch with the replacement one they sent me. They did however let me keep the old switch that POE was not working on. Now I am interested in the cold reboot to see if POE works on it. Do you think just remove all cables then power up and cosole into it and see if POE works again?

[Leo Laohoo]

First step to troubleshooting this perennial bug would be to cold reboot the entire stack. 

IMPORTANT:  Cold reboot is just a workaround.  This is not a permanent fix.  The bugs are due to the MOSFET slowly degrading over time.  

The only permanent fix is to RMA the appliance once it is proven that the ports (plural) work after a cold reboot of the entire stack.  In some extreme cases, multiple cold reboot are required.

[paul driver]

Hello

If you upgrade the stack you my need to wait for the microcode to upgrade also, which can take as long as 30 mins after reboot
So this call for KISS (Keep It Stupid,Simple),

1)add the current stack ios to the replacement switch's flash,
2)attach replacement switch via stack ports,
3)power up replacement switch
Done...