Adding switch to existing stack

rakem

Hi, we currently have two 3750s in a stack and wish to add a third.



I have made sure that the IOS on the new switch is the same as the existing switches and have entered this command on the current stack



switch 3 provision ws-c3750g-24ps



So currently there are two stacking cables in use.

Port 1 on switch1 goes to port 2 on switch2 and

Port 2 on switch1 goes to port 1 on switch2



So they are configured in a cross over type setup.



Question1) - Can i unplug one of these cables without affecting the stacks operation?

Question2) - would the best way to hook up the new switch be



Switch1 port 1 -> switch2 port2

Switch1 port2 -> switch3 port1

Switch2 port1 -> switch3 port2



I know that i have to connect the new switch while it is powered off, then power it up once all the stack cables are connected. I'm just a bit worreid about unplugging one of the current stack cables.

tiersten

rakem wrote: »

Question1) - Can i unplug one of these cables without affecting the stacks operation?

If the two cables are okay then yeah, you can unplug one without affecting it. Be aware that you'll have half the bandwidth though during that period.

Run "show switch stack-ports" to check that it is okay on both ports on both switches.

rakem wrote: »

Question2) - would the best way to hook up the new switch be

Doesn't matter. You've only got 3 switches so they will only ever be in a loop. The choice would be whether to use P1 or P2 but they're equivalent anyway.

S1P1 -> S2P2
S2P1 -> S3P2
S3P1 -> S1P2

rakem

Well did this tonight.... unplugged the cable from Port1 on switch 2, had a look on my console and a see every Gi2/0/x interface going down, all lights on switch2 went off as well.

Decided to push on, hooked up the new switch, powered it on and the whole stack reboots...

After about 3 or 4 minutes the stack is up and the new switch is ready..... any thoughts on what i lost all of switch 2, then when the new one was connected the stack rebooted?