3750 stack issue

[Cisco Freak]

Hello,

I have two Cisco 3750 switches configured in stack.

Switch#sh switch                           
Switch/Stack Mac Address : 001b.8f73.5580
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
 1       Member 001b.543e.6780     15     0       Ready               
*2       Master 001b.8f73.5580     1      0       Ready               

I see that switch 1 has a priority of 15. Still its not the switch master. Please help me to understand why Switch1 is not becoming master.

Also, in the running config I don't see anywhere we configure the switch priority as 15. I am wondering how it became 15 without configuration.

Switch#sh run | i priority                 
Switch#remote command 1 sh run | i priority
Switch : 1 :
------------


Switch#

CF

[paul driver]

Hello

Have you recently performed priority change or install of a new switch to the stack are they running the same ios and feature set?
Have you tried reloading the stack?

sh switch detail
sh version

res

Paul

[Cisco Freak]

No, I have't tried reloading the switch. Both swithches are switch same IOS and feature set.

Switch#sh switch detail
Switch/Stack Mac Address : 001b.8f73.5580
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
 1       Member 001b.543e.6780     15     0       Ready               
*2       Master 001b.8f73.5580     1      0       Ready               



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

Switch#sh ver
Cisco IOS Software, C3750 Software (C3750-IPBASEK9-M), Version 12.2(55)SE4, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2011 by Cisco Systems, Inc.
Compiled Tue 06-Sep-11 02:59 by prod_rel_team
Image text-base: 0x01000000, data-base: 0x02D00000

ROM: Bootstrap program is C3750 boot loader
BOOTLDR: C3750 Boot Loader (C3750-HBOOT-M) Version 12.2(44)SE5, RELEASE SOFTWARE (fc1)

Switch uptime is 10 weeks, 6 days, 9 hours, 47 minutes
System returned to ROM by power-on
System restarted at 00:16:52 Pacific Thu Sep 3 2015
System image file is "flash:/c3750-ipbasek9-mz.122-55.SE4.bin"


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cisco WS-C3750G-24TS-1U (PowerPC405) processor (revision E0) with 131072K bytes of memory.
Processor board ID FOC1113Y14U
Last reset from power-on
3 Virtual Ethernet interfaces
56 Gigabit Ethernet interfaces
The password-recovery mechanism is enabled.

512K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address       : 00:1B:8F:73:55:80
Motherboard assembly number     : 73-10219-07
Power supply part number        : 341-0098-02
Motherboard serial number       : FOC1107121V
Power supply serial number      : AZS110703WF
Model revision number           : E0
Motherboard revision number     : B0
Model number                    : WS-C3750G-24TS-S1U
System serial number            : FOC1113Y14U
Top Assembly Part Number        : 800-26859-01
Top Assembly Revision Number    : C0
Version ID                      : V03
CLEI Code Number                : CNMWS00ARC
Hardware Board Revision Number  : 0x09


Switch Ports Model              SW Version            SW Image                 
------ ----- -----              ----------            ----------               
     1 28    WS-C3750G-24TS-1U  12.2(55)SE4           C3750-IPBASEK9-M         
*    2 28    WS-C3750G-24TS-1U  12.2(55)SE4           C3750-IPBASEK9-M         


Switch 01
---------
Switch Uptime                   : 10 weeks, 6 days, 8 hours, 22 minutes
Base ethernet MAC Address       : 00:1B:54:3E:67:80
Motherboard assembly number     : 73-10219-07
Power supply part number        : 341-0098-02
Motherboard serial number       : FOC11105719
Power supply serial number      : AZS1109067V
Model revision number           : E0
Motherboard revision number     : B0
Model number                    : WS-C3750G-24TS-S1U
System serial number            : FOC1111Y1KH
Top assembly part number        : 800-26859-01
Top assembly revision number    : C0
Version ID                      : V03
CLEI Code Number                : CNMWS00ARC

Configuration register is 0xF

Switch#

[Richard Bradfield]

Please see this extract from

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

When is the stack master elected?

• When the whole switch stack is reset¹

• When the stack master is reset or powered off

  Note: If you reset the stack master, it would reset the whole stack.

• When the stack master is removed from the stack

• When the stack master switch has failed

• The switch stack membership is increased by if you add powered-on standalone switches or switch stacks.¹

¹Within these events, the current stack master has a greater chance to get re-elected.

[paul driver]

Hello

Can i suggest reload the stack when applicable

res
Paul

[Cisco Freak]

Yes, I can do it.

But I want to replace the switch 1 with a new one. I am wondering if I replace it with a new one, whether it will sync the config from the current master which is switch 2.

CF

[paul driver]

Hello

It looks like switch 1 one was powered up first, and then switch 2 but was they connected when you powered the 2nd switch up or did you just attach it whilst it was powered on?

I would reboot the stack and then if you wish remove the whatever switch you wish then renumber one you wish to keep and the one you wish to remove and then disconnect the old switch and unprovison it.

res
Paul

[Richard Bradfield]

When a switch joins a stack it will get the current config from the stack,all switches in a stack have a copy of the configuration of the stack. To be on the safe side you can delete the config and vlan.dat of the switch you are going to add to the stack.

I have nver had any problems replacing switches in a stack it all works well