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PostPosted: Mon Sep 05, 2011 6:56 pm 
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I have a following Cisco StackWise setup:
Code:
Switch Ports Model              SW Version            SW Image                 
------ ----- -----              ----------            ----------               
*    1 28    WS-C3750G-24TS-1U  12.2(53)SE1           C3750-IPBASEK9-M         
     2 28    WS-C3750G-24TS-1U  12.2(53)SE1           C3750-IPBASEK9-M         
     3 12    WS-C3750G-12S      12.2(53)SE1           C3750-IPBASEK9-M         


As you can see, switch 1 is selected as a stack master. Is there a service interruption if I do:

Code:
switch 1 priority 5
switch 2 priority 15


..which sets the priority of the first switch lower than the second one? In addition, when does the stack-master election occur? According to Cisco documentation, it is a part of the bootup process, but is there a way to manually force stack-master election once I have changed the priority? :roll:


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PostPosted: Mon Sep 05, 2011 8:38 pm 
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You won't notice a thing by changing the priorities on the switches. You'll have to lose connectivity to switch 1 to change the master.

Reload switch 1 and 2 will become the master. That's if all the configuration is right between switch 2 and 3.


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PostPosted: Tue Sep 06, 2011 1:33 am 
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michoudi wrote:
You won't notice a thing by changing the priorities on the switches. You'll have to lose connectivity to switch 1 to change the master.

Reload switch 1 and 2 will become the master. That's if all the configuration is right between switch 2 and 3.

So the master election takes place only during the reboot? In other words those commands:

Code:
switch 1 priority 5
switch 2 priority 15


..take affect only in case the current stack master is reloaded?


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PostPosted: Tue Sep 06, 2011 4:19 am 
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m4rtin wrote:
michoudi wrote:
You won't notice a thing by changing the priorities on the switches. You'll have to lose connectivity to switch 1 to change the master.

Reload switch 1 and 2 will become the master. That's if all the configuration is right between switch 2 and 3.

So the master election takes place only during the reboot? In other words those commands:

Code:
switch 1 priority 5
switch 2 priority 15


..take affect only in case the current stack master is reloaded?


Correct.

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PostPosted: Tue Sep 06, 2011 8:40 pm 
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m4rtin wrote:
So the master election takes place only during the reboot?

Or when two masters become connected.


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PostPosted: Wed Sep 07, 2011 11:35 am 
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higher priority is better, so the one you always want to boot master should be priority 15,


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PostPosted: Thu Sep 08, 2011 6:05 pm 
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What is the best practise regarding master selection? I mean should one keep a switch in the stack with manual priority 15 so it's always sure that this particular switch will become the master one? :roll:

In addition, how do you upgrade software in stack? The first idea I have in case of a stack with three switches is to copy IOS image to a flash memory of each switch, force boot from the new image and finally quickly reload stack members and finally stack master:

Code:
copy tftp flash1: !copies c3750-ipbasek9-mz.122-53.SE1.bin from TFTP server to flash memory
config t
boot system flash:/c3750-ipbasek9-mz.122-53.SE1.bin
end
copy tftp flash2:
config t
boot system switch 2 flash2:/c3750-ipbasek9-mz.122-53.SE1.bin
end
copy tftp flash3:
config t
boot system switch 3 flash3:/c3750-ipbasek9-mz.122-53.SE1.bin
end
reload slot 3
reload slot 2
reload


What do you think? :roll:


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PostPosted: Thu Sep 08, 2011 9:12 pm 
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You should use the archive command to upgrade the software on the stack, and you will need to reload the whole stack at the same time to make it work correctly.


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PostPosted: Fri Sep 09, 2011 10:47 pm 
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1KrazyFool wrote:
You should use the archive command to upgrade the software on the stack, and you will need to reload the whole stack at the same time to make it work correctly.


On the other hand, if one don't want to have HTTP server files in the switch, it would be more convenient to go with the traditional upgrading methods. Following should work:

Code:
copy tftp flash1: !copies c3750-ipbasek9-mz.122-53.SE1.bin from TFTP server to flash memory
copy tftp flash2:
copy tftp flash3:
config t
boot system switch all flash:/c3750-ipbasek9-mz.122-53.SE1.bin
exit
write
reload


Am I correct, that releoad in a switch stack reloads the stack-master as well as stack-members? :roll:


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PostPosted: Sat Sep 10, 2011 10:22 pm 
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There are command switches to the archive command that can install the image only, with no http files. It can also reload the stack when all the switches have the image loaded. Really, use the archive command. It does everything you need in one command.

And yes, a singular 'reload' command would reload the whole stack, master and all.


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PostPosted: Sun Sep 25, 2011 2:38 pm 
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1KrazyFool wrote:
There are command switches to the archive command that can install the image only, with no http files. It can also reload the stack when all the switches have the image loaded. Really, use the archive command. It does everything you need in one command.

And yes, a singular 'reload' command would reload the whole stack, master and all.


1KrazyFool, thanks!


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PostPosted: Wed Aug 15, 2012 3:17 am 
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If I connect STACK1 port on switch1 to STACK1 port on switch2 and STACK2 port on switch1 to STACK2 on switch2 like this:

Image

..then according to "sh switch neighbors" output I have made crossed connection:

Code:
C3750G#sh switch neighbors       
  Switch #    Port 1       Port 2
  --------    ------       ------
      1         2             2 
      2         1             1 

C3750G#sh switch stack-ports     
  Switch #    Port 1       Port 2
  --------    ------       ------
    1           Ok           Ok   
    2           Ok           Ok   

C3750G#sh switch stack-ring speed

Stack Ring Speed        : 32G
Stack Ring Configuration: Full
Stack Ring Protocol     : StackWise
C3750G#


Why is it so? Or am I correct that this does not matter if one connects stack-cables in crossed formation or straight?

//looks like it is the switch number under ports, not the port numbers


In addition, am I correct that if the StackWise ring is broken(both stack cables are removed) and then one reconnects StackWise cable(s), then all the reconnected switches will reload in order to become stack members?


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