KB ID 0001444

Problem

You can stack up to 8 2960-X Switches*, you will require the stack modules and cables, (shown below). 

*Note: If you are studying for an exam, and the question is StackWize the answer is 9.

Solution

Stack Modules: Power down the switch, remove the blanking plate and fit the module, then when powered on you can use a show inventory command to make sure the module has been detected correctly.

Switch#show inventory
NAME: "1", DESCR: "WS-C2960X-48FPD-L"
PID: WS-C2960X-48FPD-L , VID: V07 , SN: FCW2213B2XX

NAME: "Switch 1 - FlexStackPlus Module", DESCR: "Stacking Module"
PID: C2960X-STACK , VID: V02 , SN: FOC221410XX

Switch#

Setting a Stack Master: If you do nothing and simply connect up a stack, then power it on, the switches have an ‘election’ and the one with the lowest MAC address becomes the master. This is a bit bobbins, so I prefer to configure a switch to be master by increasing its priority. This is a number between 1 and 15 (Highest wins) and all switches have a priority of 1 out of the box.

I typically set the ‘top’ switch as the stack master and set its priority to 15.

Switch#configure terminal
Switch(config)#switch 1 priority 15
Changing the Switch Priority of Switch Number 1 to 15
Do you want to continue?[confirm]{Enter}	
New Priority has been set successfully

TO CONFIRM
Switch#show switch
Switch/Stack Mac Address : 5061.bf51.dd80
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 5061.bf51.dd80     15     4       Ready


Switch#

Then cable the switches together with the stack cables. If you are cabling two switches together then cable like so;

If cabling more switches , then cable stack port 1 of a switch, to port 2 of the switch below it, and keep going, then on the bottom switch cable port 1 back up to port 2 on the top switch (to make a ring).

Then power everything on, check the stack is up 

Switch#show switch detail
Switch/Stack Mac Address : 5061.bf51.dd80
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 5061.bf51.dd80     15     4       Ready
 2       Member 5061.bf51.de00     1      4       Ready

         Stack Port Status             Neighbors
Switch#  Port 1     Port 2           Port 1   Port 2
--------------------------------------------------------
  1        Ok         Ok                2        2
  2        Ok         Ok                1        1

Note: You can use ‘show switch stack-ports‘ to get the second half of that output only.

Check the switch stack ring;

Switch#show switch stack-ring speed

Stack Ring Speed        : 20G
Stack Ring Configuration: Full
Stack Ring Protocol     : FlexStack

My Ring speed is only 20G? Yes thats correct 🙂

Cisco Say it’s supposed to be 80G? Yeah, marketing piffle sorry, with two rings at full duplex it’s rated at four times the bandwidth that’s where they get this figure from.

You can now configure all the interfaces from one management IP, note to select all the interfaces use the following syntax

Switch(config)#interface range gi1/0/1-48,gi2/0/1-48

Related Articles, References, Credits, or External Links

Cisco Stacking 3750 Switches