Adding 3rd switch to stack without breaking stack

[mahesh18]

Hi Everyone,

I need to add 3rd switch to stack.Currently it has 2 switches in stack and it is running some critical applications so i can not afford downtime.

Current cable setup is

3750#sh switch
Switch/Stack Mac Address : 001b.90e7.d480
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 001b.90e7.d480     10     0       Ready
 2       Member 001b.90e7.0580     8      0       Ready

3750#sh switch stack-ports
  Switch #    Port 1       Port 2
  --------    ------       ------
    1           Ok           Ok
    2           Ok           Ok

3750#sh switch neighbors
  Switch #    Port 1       Port 2
  --------    ------       ------
      1         2             2
      2         1             1

Need to know how can i bring 3rd cable to stack without downtime.

Regards

MAhesh

[Reza Sharifi · Accepted solution]

Hi Mahesh,

Here is the instruction on how to add a switch to a stack as a member/slave.

Make sure to turn off the switch before connecting the stack cable.

http://www.cisco.com/c/en/us/support/docs/switches/catalyst-3750-series-switches/71925-cat3750-create-switch-stks.html#stack3

Also, I would still have an outage window when doing this just in case something goes wrong.  It is always good to be safe than sorry.

Good Luck

Reza

[mahesh18]

Many thanks Reza.

Regards

MAhesh

[Reza Sharifi]

Glad to help Mahesh!!

How have you been?

Has been a long time.

Thanks,

Reza

[mahesh18]

I am fine.

Mostly working on firewalls,IPS devices these days.

But routing and switching comes also under my job responsibility

Regards

MAhesh