Troubleshooting tips for Cisco 3750X Stack power feature

Introduction
Cisco Stack Power technology is a new feature introduced in the Cisco catalyst 3750-X
series switches that aggregates all of the available power in a stack of swithces and
anages it as one coon power tool!
"he catalyst 3750X has two power supplies per syste which allows the power load to
be split between the! "his syste increases tha a#iu power per port to 30 $atts
to eet the P%&' standard ()0*!3at+! $ih P%&', a -) port syste would need .--0
$atts to provide 30 $atts per port per powered device! Systes with few powered
devices ight re/uire only one Power Supply in which case second Power Supply can
provide one-to-one redundancy for active Power Supply!
0 power stack can not contain ore than four switches and Power Supplies of these
switches can be anaged as one large Power Supply that provides power to all
switches! 1n this way, any faulty Power Supply in a single switch can be replaced without
taking that switch offline!
Stack Power also allows deployent of e#pandable Power Syste, XPS **00 to create
large power pools! "his syste fors a star topology which shares power with upto 2
swicthes and provides iproved reliability, availability and efficiency!
Requirements
"here are no specific re/uireents!
Troubleshooting tips
%ne of the ost coon issue seen with Stack Power feature is that even when the
switches are in stack, the stack topology is still standalone which eans that the power
sharing feature has not started yet! "he coands used to see this issue and correct it
are3
1
show stack-power is the coand which is used to check whether the feature has
started or not! $hen we don4t have any issues, the output would be soething like3
Switch5 show stack-power
Power stack nae3 Powerstack.
Stack ode3 Power sharing
Switch .3
Power budget3 *06
7ow port priority value3 .7
8igh port priority value3 .6
Switch priority value3 *
Port 0 status3 9ot shut
Port : status3 9ot shut
9eighbor on port 03 00**!bdcf!ab00
9eighbor on port :3 00**!bdd0!-3)0
0nd, in cases when we don;t have this feature started yet we will see soething like3
Switch5 show stack-power
Power stack nae3 Powerstack-.
Stack ode3 Power sharing strict
Stack topology: Standalone
Switch 33
Power budget3 .063
7ow port priority value3 **
8igh port priority value3 .3
Switch priority value3 -
ort ! status: Shut
ort " status: Shut
9eighbor on port .3 0000!0000!0000
2
9eighbor on port *3 0000!0000!0000
"hese ports . and * are power ports and should be enabled for use of power sharing
feature! "hese ports can be enabled by using following coand in &X&C ode3
switch5stack-power switch 3 port . enable
switch5stack-power switch 3 port * enable
Please note that these coands are to be issued in &X&C ode! %ne very coon
istake is to type these coands in global configuration ode!
%PLATFORM_STACKPOWER-4-UNDER_BUDGET:
"his essage is observed even when the power supplies looks %< otherwise!"his
essage is also observed in cases when we have =ust got the power feature started by
enabling power ports!
"here are few options available to overcoe this issue3
.! !Power cycle not reload the switch which is issuing these essages (like switch * in
above error essage+
*! Put the particular switch or all the switches in stack in standalone ode, this can be
done by issuing following coand3
Switch(config+5stack-power switch *
Switch(config-switch-stackpower+5standalone
%nce this is done, wait for 60-20 seconds and see if the error essage goes away! %nce
the error essage ceases, put the switch>switches out of standalone ode by using ?no
standalone? coand!
%PLATFORM_STACKPOWER-4-PRIO_CONFLICT:
"here is no specific troubleshooting for this issue however, certain guidelines can be
followed to avoid such situations3
@ou can configure priority of a switch and of a powered device! "his priority deterines
which switch>port will shut down first in case of power shortage! @ou can configure three
priorities per syste (switch+3
.! "he syste (switch+ priority!
*! Priority of high priority P%& ports!
3! Priority of low priority P%& ports!
3
%n any swicth, the switch priority should be lower than the priority of P%& ports and the
high priority values ust be set lower than the low priority values! 1t is recoended that
you configure different priority values for each switch and its high priority and low priority
ports! "his liits the nuber of devices shut down at a tie during loss of power! 1f you
try to configure sae priority values at different swiitches, the configuration will be
allowed but you will receive an error essage!
"he default priority ranges, if none are configured, are .-2 for switches, .0-.) for high-
priority ports, and .2-*7 for low-priority ports!
Troubleshooting examples
roble# $escription:
0fter configuring stack Aode redundantB, power redundancy through stack-wise not
working
Syptos3
0n &rror Cessage3
%PLATFORM_STACKPOWER-4-REDUNDANCY_LOSS: Switch !" #$w%& "t'c( )$"t
&%*+,*',c- ',* i" ,$w $#%&'ti,. i, #$w%& "h'&i,.
/$*%
Switch3750-X5show stack-power
Power stack nae3 Powerstack.
Stack ode3 Dedundant
Stack topology3 Standalone
Switch *3
Power budget3 .663
7ow port priority value3 **
8igh port priority value3 .3
Switch priority value3 -
ort ! status: Shut
4
Port * status3 Connected
9eighbor on port .3 0000!0000!0000
9eighbor on port *3 f)66!f*5a!7d00
%utput of the coand Ashow stack powerB shows the port status as AShutB
%utput of the coand ?show environent power?
Switch3750-X5sho en% power
S$ P1E Serial5 Status Sys Pwr Po&
Pwr$atts
----- ------- -------------- --------------- --------------- ------
--------------
.0 C3<X-P$D-7.5$0C 000000000F- %< Good Good 7.5>0
.: 9ot Present
"roubleshooting Steps3
.! Dedundancy is configured however the power stack ports are shut
*! &nable all power stack ports by coand Astack-power switch HnuberI port
HnuberI enableB
Switch3750-X5stack-power switch * port . enable
1t is referred from https://supportforums.cisco.com/document/72421/troubleshooting-tips-3750x-
stac-po!er-feature
&ore related:
Cisco 3750-X Series Switches %verview
Cisco Catalyst 3750-X and 3560-X &#press Setup
Cisco Catalyst 3750-X JS 3560-X Series Switches
Cisco Catalyst 3750-X and 3560-X 9etwork Codules
Cisco 3)50 Series Switches Js Cisco 3750-X Switches
"he :enefits of Cisco Catalyst 3750-X and 3560-X 1P Services Switch
&ore Cisco products and 'e%iews you can %isit: http://!!!.3anet!or.com/blog

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