Add New Switch to Stack

[PolarPanda]

Hi

I have an existing stack switch 3850 with 3 members and need to add the 4th one. I have the procedure at below, can any Cisco expert help to validate if it's correct or not?

1. The 4th one is used one with config, so i need "erase start-up config" or "wr erase". which one is better? or neither?
2. Upgrade 4th one to the exact same iOS as the stack
3. On switch 4: switch 4 priority 5 (make sure the other 3 in switch stack have high priority), then power off.
4. On master switch: switch 4 provision WS-xxxxx.
5. Connect stack-wise cables: connect switch 3 P1 to Switch 4 P2; connect switch 1 P2 to switch 4 P1
6. Connect stack power cables: connect switch 3 A to switch 4 B; connect switch 1 B to switch 4 A
7. Connect power supplies on switch 4
8. "Show switch" to see if everything is ok

Thank you.

[Reza Sharifi · Accepted solution]

Hi,

"wr erase" should be fine.

I would reverse 5 and 6 by turning on the PSUs first and then connect the stacking power cables.

Everything else looks good.

HTH

[Reza Sharifi]

And one more thing, make sure the new switch has the same license as the rest of the stack.

[PolarPanda]

you mean reverse 6 and 7? Connect AC power first then stack power?

[Reza Sharifi]

you mean reverse 6 and 7? Connect AC power first then stack power?

Yes, exactly!

[PolarPanda]

What's the reason? why reverse the order is better?

[Reza Sharifi · Accepted solution]

Because when you use the PSU, there is no power sharing, and usually enough power to power up the switch. So, once the switch is up and running and added to the stack, you can simply connect the power stacking and verify the neighborship.

HTH