Using the deterministic method

Install a Stacking Module into a switch and then boot the switch, as described in the ArubaOS-Switch Installation and Getting Started Guide.
Make sure that stacking is enabled for the switch:
1. Enter the show stacking command.
2. If stacking is disabled, enter stacking enable (in global config context). This command causes the switch to reboot.

When the switch finishes booting, enter the show stacking command again. The switch now has the status of Commander, a Member ID of 1 (one) and a default priority of 128.

show stacking output

switch# show stacking
Stack ID : NO ID - will merge upon connectivity
MAC Address : 1cc1de-4d48c0
Stack Topology : No Stack Formed
Stack Status : No Stack Formed
Uptime : 0d 0h 5m
Software Version : WB.15.11
Mbr
ID  Mac Address   Model                                 Pri Status
--- ------------- ------------------------------------- --- -------
1   1cc1de-4d48c0 HPE J9729A 2920-48G-PoE+-4SFP+ Switch  128 Commander

To generate a stack ID, enter the following command:switch(config)#stacking set-stack
(Optional) To have this switch retain its function as Commander through stack boots and other situations, increase its priority. The switch with the highest priority becomes Commander when all switches are booted simultaneously. Default priority is 128; priority can be set to any value between 1 and 255. For example, to increase a switch stacking priority to 255, enter the following command:
```
switch(config)# stacking member 1 priority 255
```
(Optional) Preconfigure the stack for the other switches that become members of the stack. You can assign a member number and a priority by using the following command for each switch:
```
switch(config)# stacking member <n> type <JxxxxA> [mac <MAC-address>]
```
where:
- n is the stacking member number for the switch
- JxxxxA is the product number of the switch (required). Any 2920 model can be installed and assume this configuration. When you specify a value for this parameter, then only a switch of this specific model type can assume this configuration
- (Optional) MAC-address can be specified if you want a specific switch to assume this provisioned configuration. If this value is entered, then the type value for the switch that has this MAC address must be correct, or a configuration error is logged and the switch is not allowed to join the stack.
(Optional) You can preconfigure a priority for the member switch with the following command:
```
switch(config)# stacking member <n> priority <x>
```
where:
- n is the stacking member number for the switch
- x is the priority (1 – 255, default 128); must be less than the priority assigned to the Commander. Priority for the Standby should be the second highest in the stack. Member switches can remain at the default priority of 128.
NOTE:
Configure the stacking type and priority with separate commands; for example:

switch(config)# stacking member 4 type J9726A

switch(config)# stacking member 4 priority 100
Connect the stacking cables to the module ports for the desired stacking topology. For example, plug ports 1 and 2 in a ring.
Install, but do not boot, Stacking Modules into the other switches that will be members of the stack.
NOTE:
Hewlett Packard Enterprise recommends that you create a ring topology for maximum throughput and resiliency of the stack. A chain topology is not recommended because any hardware or software failure in the stack causes lost ports, which increases the amount of time for recovery of full stack operation due to multiple reboots. See the ArubaOS-Switch Installation and Getting Started Guide for supported topologies.
Boot the Standby and Member switches. The second switch booted becomes the Standby; the remaining switches become Members when booted.
When all switches are booted, enter the show stacking command to confirm that the stack is operating correctly. The following example shows four switches in a chain topology.

Four switches in a chain topology

switch# show stacking
  Stack ID         : 00031cc1-de4d48c0
  MAC Address      : 1cc1de-4d48c9
  Stack Topology   : Chain
  Stack Status     : Active
  Uptime           : 1d 2h 35m
  Software Version : WB.15.11

   Mbr
   ID  Mac Address   Model                                  Pri Status
   --- ------------- -------------------------------------- --- ---------
   1   1cc1de-4d48c0 HPE J9726A 2920-48G-PoE+-4SFP+ Switch   250 Commander
   2   1cc1de-4d8680 HPE J9727A 2920-24G-PoE+-2SFP+ Switch   230 Standby
   3   1cc1de-4e3180 HPE J9728A 2920-48G-PoE+-4SFP+ Switch   128 Member
   4   78acc0-3c2180 HPE J9729A 2920-48G-4SFP+ Switch        128 Member