Power down Cisco 3750e stack of switches

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Nov 11th, 2008
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Hi guys,


I appreciate the resiliency of Cisco hardware and understand that in some cases you can simply remove the power to a switch and it will function perfectly normal next time round... but I was wondering if there was a special way to power down a stack of Cisco 3750e's? We have a stack of four and I want to ensure that when I take them down they come up cleanly!!


Any tips or advice?


Thanks


Darren

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Giuseppe Larosa Wed, 11/12/2008 - 01:00
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Hello Darren,

I would switch off starting from stack members and master as last one.

Later I would switch on the master first and all the other switch members within 20 seconds

This should helps to avoid that another switch is elected master during a transition.


Hope to help

Giuseppe


darren-carr Wed, 11/12/2008 - 02:34
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Hi Giuseppe


Thanks for the infomration. So remove the power from stack 4 -> 1 and bring them back up in the reverse? There are no commands to execute on the stack? Just physical removal?


Thanks for your help mate


Darren

MUHAMMAD SHAHEEN Wed, 11/12/2008 - 03:15
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Hi Darren,


Master Switch should have the highest priority (usually set to 15). But if the priority is not set then whichever switch has booted 1st that will be the master for that stack. In your case if the prioriy is not set and you dont know whichone is master. Then "#Show Switch" command will tell you which switch is the master. You should physically check the mac address of the master switch to find out if it is the one on the top or at the bottom or in the middle.


When you power up, just make sure the master switch is powered up 1st and power up the remaining 3 switches at least 20 second later.



Hope This Helps.......

Shaheen

Giuseppe Larosa Wed, 11/12/2008 - 04:43
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Hello Darren,

master switch can be found using show switch and be aware that is not necessary switch n.1:


see


SW-NY-C-2>sh switch

Current

Switch# Role Mac Address Priority State

--------------------------------------------------------

1 Slave 0013.c35a.c900 10 Ready

2 Slave 0013.c4fc.4680 1 Ready

*3 Master 0013.80b5.b280 9 Ready

4 Slave 0013.c34c.3e00 8 Ready


In my case master is in position 3 and you see that isn't the one with the highest configured priority because a fourth switch was added later to the stack



Hope to help

Giuseppe

goku-sun Fri, 10/01/2010 - 03:42
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Hi all,


I have the very same situation but I just have 3 more questions and can't get the answers after many searches, could you guys share if you had similar experiences or ideas?


Say SW-1 is the master with highest priority(say 15), SW-2 to SW-4 are member switches


1) For Powering off, should I power off switch members in specific order from SW-4 to SW-2 or just in go? Are there any difference if the switch member priorities are SAME (say 1) or different (of course less than 15) ?


2) For Powering on, after power on SW-1, wait for > 20s, then should I power on SW-2 to SW-4 in specific prder or just in one go? Are there any difference

if the slave switch priorities are SAME (say 1) or different?


3) If the order of powering OFF or ON is incorrect, will the switch members be re-numbered?


Many thanks in advance!

Goku

mmoulson1 Fri, 01/14/2011 - 05:55
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Goku,


1) As long as you save your config the order you power off does not really make a difference. If you turned off the master first then another switch would be re-elected as the master but as you are powering everything off that does not matter.

2) Powering on, I always power on in order so master, 2nd, 3rd, 4th etc. but just flick them on one after another. You should not wait 20sec, the switches will wait (20sec I believe) for the master election during boot up, so a long as you have set your priorities then they should come up in the order they went down. No difference in the slave priority as they will always come up as their own number, this only comes into play if the master is not available, who will be the master in its place etc.

3) The switch will remember its number in the stack so for example you power on switches 1 and 3 but not 2, switch 3 will come up as switch 3 with its existing config etc.

I always label my switches and config them in the lab. When they are shipped to site it is clear which order they should be stacked in so they come up correctly.

Hope that helps

Matt

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