Thursday, October 10, 2019

Stacking a Cisco 2960-X Switch

I've stacked Cisco Catalyst 2960S, 3650, 3750-X switches in my previous posts, but this time I'll configure and stack four Cisco 2960-X switches. The Cisco 2960-X uses the FlexStack module and cable.




Use a number #2 Phillips-head screwdriver to remove the blank module cover and insert the FlexStack module located behind the switch.


I followed stacking for the four switches using the Cisco guide and looked something below.




After connecting all the FlexStack cables, I first powered on the Master (topmost) switch and waited until it's fully booted up. Then I powered on the Member switches in sequence (from top to bottom) in order to avoid the stack election process. I just connected the console cable to the console port on the Master switch and observed the bootup and stacking process.


###################################################################################
SM: All possible switches in stack are booted up

POST: Inline Power Controller Tests : Begin
POST: Inline Power Controller Tests : End, Status Passed

POST: Thermal, Fan Tests : Begin
POST: Thermal, Fan Tests : End, Status Passed

POST: PortASIC Stack Port Loopback Tests : Begin
POST: PortASIC Stack Port Loopback Tests : End, Status Passed

POST: PortASIC Port Loopback Tests : Begin
POST: PortASIC Port Loopback Tests : End, Status Passed

POST: EMAC Loopback Tests : Begin
POST: EMAC Loopback Tests : MAC Loopback Passed
POST: EMAC Loopback Tests : PHY Loopback Passed
POST: EMAC Loopback Tests : End, Status Passed

Election Complete
Switch 1 booting as Master
Waiting for Port download...Complete
Initializing Port Extension Feature Support...


This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

If you require further assistance please contact us by sending email to
export@cisco.com.

cisco WS-C2960X-24PS-L (APM86XXX) processor (revision T0) with 524288K bytes of memory.
Processor board ID FOC23161234
Last reset from power-on
1 Virtual Ethernet interface
1 FastEthernet interface
28 Gigabit Ethernet interfaces
The password-recovery mechanism is enabled.

512K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address       : 78:02:B1:AA:12:34
Motherboard assembly number     : 73-16694-07
Power supply part number        : 341-0528-02
Motherboard serial number       : FOC23159GPG
Power supply serial number      : LIT23132X5K
Model revision number           : T0
Motherboard revision number     : B0
Model number                    : WS-C2960X-24PS-L
Daughterboard assembly number   : 73-14200-03
Daughterboard serial number     : FOC231608BT
System serial number            : FOC23161234
Top Assembly Part Number        : 68-100472-04
Top Assembly Revision Number    : C0
Version ID                      : V06
CLEI Code Number                : CMMZ200ARA
Daughterboard revision number   : B0
Hardware Board Revision Number  : 0x19


Switch Ports Model                     SW Version            SW Image                
------ ----- -----                     ----------            ----------              
*    1 28    WS-C2960X-24PS-L          15.2(2)E7             C2960X-UNIVERSALK9-M    


Press RETURN to get started!


*Mar  1 00:00:27.808: Read env variable - LICENSE_BOOT_LEVEL =
*Jan  2 00:00:00.150: %IOS_LICENSE_IMAGE_APPLICATION-6-LICENSE_LEVEL: Module name = c2960x_lanbase Next reboot level = lanbase and License = lanbase
Sep 19 08:13:44.202:  Flexstack module is 1
Sep 19 08:13:44.300: %HPAA:hpaa_port_bitmap_init:254:n_ports = 28, sizeof (**hpaa_port_bitmap.bitlist_array) = 16
Sep 19 08:16:34.498: %STACKMGR-4-SWITCH_ADDED: Switch 1 has been ADDED to the stack
Sep 19 08:16:35.836: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to down
Sep 19 08:16:35.836: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0, changed state to down
Sep 19 08:16:35.889: %SMI-5-CLIENT:  Smart Install Client feature is enabled. It is recommended to disable the Smart Install feature when it is not actively used. To disable feature execute 'no vstack' in configuration mode
Sep 19 08:16:37.675: %SPANTREE-5-EXTENDED_SYSID: Extended SysId enabled for type vlan
Sep 19 08:17:03.543: %STACKMGR-5-SWITCH_READY: Switch 1 is READY
Sep 19 08:17:03.543: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 1 Switch 1 has changed to state DOWN
Sep 19 08:17:03.543: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 1 has changed to state DOWN
Sep 19 08:17:03.921: %STACKMGR-5-MASTER_READY: Master Switch 1 is READY
Sep 19 08:17:03.935: %SYS-5-RESTART: System restarted --
Cisco IOS Software, C2960X Software (C2960X-UNIVERSALK9-M), Version 15.2(2)E7, RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2017 by Cisco Systems, Inc.
Compiled Wed 12-Jul-17 13:06 by prod_rel_team
Sep 19 08:17:04.039: %PLATFORM-6-FLEXSTACK_INSERTED: FlexStack module inserted in Switch 1.
Sep 19 08:17:05.885: %LINK-3-UPDOWN: Interface FastEthernet0, changed state to down
Sep 19 08:17:06.378: %USB_CONSOLE-6-MEDIA_RJ45: Console media-type is RJ45.
Sep 19 08:17:06.895: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0, changed state to down


         --- System Configuration Dialog ---

Enable secret warning
----------------------------------
In order to access the device manager, an enable secret is required
If you enter the initial configuration dialog, you will be prompted for the enable secret
If you choose not to enter the intial configuration dialog, or if you exit setup without setting the enable secret,
please set an enable secret using the following CLI in configuration mode-
enable secret 0 <cleartext password>
----------------------------------
Would you like to enter the initial configuration dialog? [yes/no]: no
Switch>
Sep 19 08:17:56.472: SMI Director is not configured, disabling SMI
Sep 19 08:17:56.472: disable_smartinstall_operation:Disabling SMI
Switch>
Switch>show switch
Switch/Stack Mac Address : 7802.b1aa.1234
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 7802.b1aa.1234     1      4       Ready              


I used the show switch command to check the status of the switch stack. Notice the changes on the Member switch State.

Switch>
Sep 19 08:19:47.257: %PNP-6-PNP_DISCOVERY_STOPPED: PnP Discovery stopped (Aborted by non-PnP bootstrapping)
Sep 19 08:20:03.968: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 1 Switch 1 has changed to state UP
Switch>
Switch>show switch
Switch/Stack Mac Address : 7802.b1aa.1234
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 7802.b1aa.1234     1      4       Ready              
 2       Member 0077.8db5.4567     1      6       Progressing        


Sep 19 08:20:36.208: %STACKMGR-4-SWITCH_ADDED: Switch 2 has been ADDED to the stack
Switch>
Switch>show switch
Switch/Stack Mac Address : 7802.b1aa.1234
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 7802.b1aa.1234     1      4       Ready              
 2       Member 0077.8db5.4567     1      4       Initializing       


Switch>
Sep 19 08:20:44.122: %STACKMGR-5-SWITCH_READY: Switch 2 is READY
Sep 19 08:20:44.122: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 1 Switch 2 has changed to state UP
Sep 19 08:20:44.122: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state DOWN
Switch>
Switch>
Sep 19 08:20:47.515: %STACKMGR-5-SWITCH_READY: Switch 2 is READY (Switch-2)
Sep 19 08:20:48.879: %USB_CONSOLE-6-MEDIA_RJ45: Console media-type is RJ45. (Switch-2)          
Sep 19 08:20:48.914: %CFGMGR-4-SLAVE_WRITING_STARTUP_CFG: only master can do that (Switch-2)
Sep 19 08:20:48.914: %CFGMGR-4-SLAVE_WRITING_STARTUP_CFG: only master can do that (Switch-2)
Switch>
Switch>show switch
Switch/Stack Mac Address : 7802.b1aa.1234
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 7802.b1aa.1234     1      4       Ready              
 2       Member 0077.8db5.4567     1      4       Ready              


Switch>
Sep 19 08:24:35.962: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 1 has changed to state UP
Switch>
Switch>show switch
Switch/Stack Mac Address : 7802.b1aa.1234
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 7802.b1aa.1234     1      4       Ready              
 2       Member 0077.8db5.4567     1      4       Ready              
 3       Member 7802.b1aa.6789     0      0       Waiting            


Switch>
Switch>show switch
Switch/Stack Mac Address : 7802.b1aa.1234
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 7802.b1aa.1234     1      4       Ready              
 2       Member 0077.8db5.4567     1      4       Ready              
 3       Member 7802.b1aa.6789     1      6       Progressing        


Switch>
Switch>
Sep 19 08:25:07.443: %STACKMGR-4-SWITCH_ADDED: Switch 3 has been ADDED to the stack
Sep 19 08:25:07.450: %STACKMGR-4-SWITCH_ADDED: Switch 3 has been ADDED to the stack (Switch-2)
Switch>
Switch>show switch
Switch/Stack Mac Address : 7802.b1aa.1234
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 7802.b1aa.1234     1      4       Ready              
 2       Member 0077.8db5.4567     1      4       Ready              
 3       Member 7802.b1aa.6789     1      4       Initializing       


Switch>
Sep 19 08:25:16.605: %STACKMGR-5-SWITCH_READY: Switch 3 is READY
Sep 19 08:25:16.605: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 1 Switch 3 has changed to state DOWN
Sep 19 08:25:16.605: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 3 has changed to state UP
Sep 19 08:25:15.811: %STACKMGR-5-SWITCH_READY: Switch 3 is READY (Switch-2)
Sep 19 08:25:16.643: %STACKMGR-5-MASTER_READY: Master Switch 1 is READY (Switch-3)
Sep 19 08:25:16.937: %STACKMGR-5-SWITCH_READY: Switch 2 is READY (Switch-3)
Sep 19 08:25:17.094: %STACKMGR-5-SWITCH_READY: Switch 3 is READY (Switch-3)
Switch>
Switch>show switch
Switch/Stack Mac Address : 7802.b1aa.1234
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 7802.b1aa.1234     1      4       Ready              
 2       Member 0077.8db5.4567     1      4       Ready              
 3       Member 7802.b1aa.6789     1      4       Ready              


Sep 19 08:25:20.156: %USB_CONSOLE-6-MEDIA_RJ45: Console media-type is RJ45. (Switch-3)
Sep 19 08:25:20.736: %CFGMGR-4-SLAVE_WRITING_STARTUP_CFG: only master can do that (Switch-3)
Sep 19 08:25:20.736: %CFGMGR-4-SLAVE_WRITING_STARTUP_CFG: only master can do that (Switch-3)
Sep 19 08:29:01.507: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP
Sep 19 08:29:01.737: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 1 Switch 3 has changed to state UP
Sep 19 08:29:33.705: %STACKMGR-4-SWITCH_ADDED: Switch 4 has been ADDED to the stack
Sep 19 08:29:33.673: %STACKMGR-4-SWITCH_ADDED: Switch 4 has been ADDED to the stack (Switch-3)
Sep 19 08:29:33.680: %STACKMGR-4-SWITCH_ADDED: Switch 4 has been ADDED to the stack (Switch-2)
Switch>
Switch>show switch
Switch/Stack Mac Address : 7802.b1aa.1234
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 7802.b1aa.1234     1      4       Ready              
 2       Member 0077.8db5.4567     1      4       Ready              
 3       Member 7802.b1aa.6789     1      4       Ready              
 4       Member 7802.b183.8912     1      4       Initializing       


Switch>
Sep 19 08:29:41.695: %STACKMGR-5-SWITCH_READY: Switch 4 is READY
Sep 19 08:29:41.695: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 1 Switch 4 has changed to state UP
Switch>
Ewitch>show switch
Switch/Stac- )ac Addr9ss : 7802.b1aa.3e80
                              s  E  Y ( w tHhW3 
uMaent
Switch#  Role   Mac Address     Priority Version  State
----------*Jan -2-0--0-:-0---3----------------------------
O1-6 L C MaEtLr 7L0 .o1aa.3e80     1      4       Ready              



My console output was garbled when Switch 4 (the last Member switch) was added on the switch stack.

Switch>0maS
Sep 19 08:19:47.257: %PNP-6-PNP_DISCOVERY_STOPPED: PnP Discovery stopped (Aborted by non-PnP bootstrapping)
Sep 19 08:20:03.968: %STACKMGR-4-STACK_ SwitCh 2GE:s baek PDrt 1 Switch 1 has changed to state UP
Switch>
Switch>sMow-swStITCH_ADDED/ twck Mac Ads ess : 7802.b1aa.1234
                                           H/W   Iurr_nDDESwiSwhtc  4lh   Mac Address     Priority Version  State
-------------------E--------------------------------------
*1       Master 7802.b1aa.1234     d    ( 4       Ready              
 2       Member 0077.8db5.45678     1  f  t6 e is ePaolressItg        


< OUTPUT TRUNCATED>


The four Cisco 2960-X  switches are now fully stacked. Notice the switch default priority of 1.

Switch>show switch
Switch/Stack Mac Address : 7802.b1aa.1234
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 7802.b1aa.1234     1      4       Ready              
 2       Member 0077.8db5.4567     1      4       Ready              
 3       Member 7802.b1aa.6789     1      4       Ready              
 4       Member 7802.b183.8912     1      4       Ready              


You can use show version to check the IOS, MAC address and serial number of the individual switch. The IOS version should be the same for stacking to work properly. Notice the Switch uptime of the Master switch has the longest uptime since it was the first to be booted up.

Switch>enable
Switch#
Switch#show version
Cisco IOS Software, C2960X Software (C2960X-UNIVERSALK9-M), Version 15.2(2)E7, RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2017 by Cisco Systems, Inc.
Compiled Wed 12-Jul-17 13:06 by prod_rel_team

ROM: Bootstrap program is C2960X boot loader
BOOTLDR: C2960X Boot Loader (C2960X-HBOOT-M) Version 15.2(3r)E1, RELEASE SOFTWARE (fc1)

Switch uptime is 18 minutes
System returned to ROM by power-on
System restarted at 08:13:15 UTC Thu Sep 19 2019
System image file is "flash:/c2960x-universalk9-mz.152-2.E7/c2960x-universalk9-mz.152-2.E7.bin"
Last reload reason: Unknown reason


This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

If you require further assistance please contact us by sending email to
export@cisco.com.

cisco WS-C2960X-24PS-L (APM86XXX) processor (revision T0) with 524288K bytes of memory.
Processor board ID FOC23161234
Last reset from power-on
1 Virtual Ethernet interface
1 FastEthernet interface
112 Gigabit Ethernet interfaces
The password-recovery mechanism is enabled.

512K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address       : 78:02:B1:AA:12:34
Motherboard assembly number     : 73-16694-07
Power supply part number        : 341-0528-02
Motherboard serial number       : FOC23159GPG
Power supply serial number      : LIT23132X5K
Model revision number           : T0
Motherboard revision number     : B0
Model number                    : WS-C2960X-24PS-L
Daughterboard assembly number   : 73-14200-03
Daughterboard serial number     : FOC231608BT
System serial number            : FOC23161234
Top Assembly Part Number        : 68-100472-04
Top Assembly Revision Number    : C0
Version ID                      : V06
CLEI Code Number                : CMMZ200ARA
Daughterboard revision number   : B0
Hardware Board Revision Number  : 0x19


Switch Ports Model                     SW Version            SW Image                
------ ----- -----                     ----------            ----------              
*    1 28    WS-C2960X-24PS-L          15.2(2)E7             C2960X-UNIVERSALK9-M    
      2 28    WS-C2960X-24PS-L          15.2(2)E7             C2960X-UNIVERSALK9-M    
     3 28    WS-C2960X-24PS-L          15.2(2)E7             C2960X-UNIVERSALK9-M    
     4 28    WS-C2960X-24PS-L          15.2(2)E7             C2960X-UNIVERSALK9-M    


Switch 02
---------
Switch Uptime                   : 12 minutes
Base ethernet MAC Address       : 00:77:8D:B5:45:67
Motherboard assembly number     : 73-16694-07
Power supply part number        : 341-0528-02
Motherboard serial number       : FOC23044567
Power supply serial number      : LIT22464EZE
Model revision number           : T0
Motherboard revision number     : A0
Model number                    : WS-C2960X-24PS-L
Daughterboard assembly number   : 73-14200-03
Daughterboard serial number     : FOC23033X90
System serial number            : FCW23044567
Top assembly part number        : 68-100472-04
Top assembly revision number    : B0
Version ID                      : V06
CLEI Code Number                : CMMZ200ARA
Daughterboard revision number   : B0

Switch 03
---------
Switch Uptime                   : 7 minutes
Base ethernet MAC Address       : 78:02:B1:AA:67:89
Motherboard assembly number     : 73-16694-07
Power supply part number        : 341-0528-02
Motherboard serial number       : FOC23156789
Power supply serial number      : LIT23132WW6
Model revision number           : T0
Motherboard revision number     : B0
Model number                    : WS-C2960X-24PS-L
Daughterboard assembly number   : 73-14200-03
Daughterboard serial number     : FOC231596UE
System serial number            : FOC23166789
Top assembly part number        : 68-100472-04
Top assembly revision number    : C0
Version ID                      : V06
CLEI Code Number                : CMMZ200ARA
Daughterboard revision number   : B0

Switch 04
---------
Switch Uptime                   : 3 minutes
Base ethernet MAC Address       : 78:02:B1:83:89:12
Motherboard assembly number     : 73-16694-07
Power supply part number        : 341-0528-02
Motherboard serial number       : FOC23148912
Power supply serial number      : LIT23132WX2
Model revision number           : T0
Motherboard revision number     : B0
Model number                    : WS-C2960X-24PS-L
Daughterboard assembly number   : 73-14200-03
Daughterboard serial number     : FOC2316073L
System serial number            : FOC23168912
Top assembly part number        : 68-100472-04
Top assembly revision number    : C0
Version ID                      : V06
CLEI Code Number                : CMMZ200ARA
Daughterboard revision number   : B0

Configuration register is 0xF

    
Notice the switch port density when issuing a show interface status command. The first number represent the module number.

Switch#show interface status

Port      Name               Status       Vlan       Duplex  Speed Type
Gi1/0/1                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/2                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/3                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/4                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/5                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/6                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/7                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/8                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/9                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/10                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/11                     notconnect   1            auto   auto 10/100/1000BaseTX
Port      Name               Status       Vlan       Duplex  Speed Type
Gi1/0/12                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/13                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/14                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/15                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/16                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/17                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/18                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/19                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/20                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/21                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/22                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/23                     notconnect   1            auto   auto 10/100/1000BaseTX    
Port      Name               Status       Vlan       Duplex  Speed Type
Gi1/0/24                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi1/0/25                     notconnect   1            auto   auto Not Present
Gi1/0/26                     notconnect   1            auto   auto Not Present
Gi1/0/27                     notconnect   1            auto   auto Not Present
Gi1/0/28                     notconnect   1            auto   auto Not Present
Gi2/0/1                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/2                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/3                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/4                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/5                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/6                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/7                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/8                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/9                      notconnect   1            auto   auto 10/100/1000BaseTX     
Port      Name               Status       Vlan       Duplex  Speed Type
Gi2/0/10                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/11                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/12                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/13                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/14                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/15                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/16                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/17                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/18                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/19                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/20                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/21                     notconnect   1            auto   auto 10/100/1000BaseTX
Port      Name               Status       Vlan       Duplex  Speed Type
Gi2/0/22                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/23                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/24                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi2/0/25                     notconnect   1            auto   auto Not Present
Gi2/0/26                     notconnect   1            auto   auto Not Present
Gi2/0/27                     notconnect   1            auto   auto Not Present
Gi2/0/28                     notconnect   1            auto   auto Not Present
Gi3/0/1                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/2                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/3                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/4                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/5                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/6                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/7                      notconnect   1            auto   auto 10/100/1000BaseTX   
Port      Name               Status       Vlan       Duplex  Speed Type
Gi3/0/8                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/9                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/10                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/11                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/12                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/13                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/14                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/15                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/16                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/17                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/18                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/19                     notconnect   1            auto   auto 10/100/1000BaseTX    
Port      Name               Status       Vlan       Duplex  Speed Type
Gi3/0/20                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/21                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/22                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/23                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/24                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi3/0/25                     notconnect   1            auto   auto Not Present
Gi3/0/26                     notconnect   1            auto   auto Not Present
Gi3/0/27                     notconnect   1            auto   auto Not Present
Gi3/0/28                     notconnect   1            auto   auto Not Present
Gi4/0/1                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/2                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/3                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/4                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/5                      notconnect   1            auto   auto 10/100/1000BaseTX 
Port      Name               Status       Vlan       Duplex  Speed Type
Gi4/0/6                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/7                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/8                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/9                      notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/10                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/11                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/12                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/13                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/14                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/15                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/16                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/17                     notconnect   1            auto   auto 10/100/1000BaseTX     
Port      Name               Status       Vlan       Duplex  Speed Type
Gi4/0/18                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/19                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/20                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/21                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/22                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/23                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/24                     notconnect   1            auto   auto 10/100/1000BaseTX
Gi4/0/25                     notconnect   1            auto   auto Not Present
Gi4/0/26                     notconnect   1            auto   auto Not Present
Gi4/0/27                     notconnect   1            auto   auto Not Present
Gi4/0/28                     notconnect   1            auto   auto Not Present
Fa0                          notconnect   routed       auto   auto 10/100BaseTX


You'll need to hardcode the priority in order to have a permanent stack setup. The switch with the highest priority will be elected as the Master switch.

Switch#configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Switch(config)#switch 1 priority 15
Changing the Switch Priority of Switch Number 1 to 15
Do you want to continue?[confirm]
New Priority has been set successfully


Switch(config)#switch 2 priority 14
Changing the Switch Priority of Switch Number 2 to 14
Do you want to continue?[confirm]
New Priority has been set successfully


Switch(config)#switch 3 priority 12
Changing the Switch Priority of Switch Number 3 to 12
Do you want to continue?[confirm]
New Priority has been set successfully


Switch(config)#switch 4 priority 10
Changing the Switch Priority of Switch Number 4 to 10
Do you want to continue?[confirm]
New Priority has been set successfully


Switch#show switch
Switch/Stack Mac Address : 7802.b1aa.1234
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 7802.b1aa.1234    15     4       Ready              
 2       Member 0077.8db5.4567     14     4       Ready              
 3       Member 7802.b1aa.6789     12     4       Ready              
 4       Member 7802.b183.8912     10     4       Ready              


Switch#show switch detail
Switch/Stack Mac Address : 7802.b1aa.1234
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 7802.b1aa.1234    15     4       Ready              
 2       Member 0077.8db5.4567     14     4       Ready              
 3       Member 7802.b1aa.6789     12     4       Ready              
 4       Member 7802.b183.8912     10     4       Ready              

         Stack Port Status             Neighbors    
Switch#  Port 1     Port 2           Port 1   Port 2
--------------------------------------------------------
  1        Ok         Ok                2        3
  2        Ok         Ok                1        4
  3        Ok         Ok                4        1
  4        Ok         Ok                3        2


Switch#show switch stack-ring speed

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