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2021-06-09T05:42:00Z

Is it necessary to stack power cables while stacking switches in Cisco Catalyst 9300 into HA mode?

418

Hi community,

Is it necessary to stack power cables while stacking switches in Cisco Catalyst 9300 into the HA mode (I am stacking using StackWise-480)?

ITCS user
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35 Answers

author avatar
Top 5Real User

If you are asking if it is mandatory, no it is not. 


If you are asking if it is a good idea, it depends on whether you are using PoE models, and whether you are using single or double power supplies on each switch in the stack. 


If you are using single power supply for each switch, or double power supplies for some of the switches, the excess power (unused portion of the power) coming from all the switches in the stack may help in case of a failure of one of the power supplies (provided that excess power is enough to compansate for the failed power supply).


If you are using double power supplies for each switch in the stack, and actually a single power supply for each switch is sufficient, then you already have redundancy for each switch, and you may not worry about stacking the power supplies.   


If you are using PoE switches, and the power supply (power supplies) cannot quite deliver the power needed by all ports on the switch, the excess power coming from the other switches in the stack may help compansate that deficiency. 


2021-06-11T16:24:38Z
author avatarHassan Shozeb
Top 20Real User

@Ender Kefoglu Thanku soo much Sir 

author avatar
Vendor

You can do it, but you don't have to. 


We have noticed that the power stacking cables are pretty unwieldy - but the basic idea is to allow for power resilience without needing dual power supplies in every switch chassis.


if you do stack power then you need to deal with the power budgets across each stack. 


You also need to think about what happens if you lose a power strip in a rack, so several PSUs go offline at the same time.....

2021-06-18T12:10:57Z
author avatarHassan Shozeb
Top 20Real User

@Stephen Hope Thanks soo much SIr

author avatar
Top 5LeaderboardReal User

The simple answer is "no". It is not required but, for improved resilience due to power or power supply issues I would recommend it. 


One thing to remember is that when using dual power supplies it is my recommendation to have one fed from a source with ups backup and the second from a surfer protected source. By adding stack power to this recommendation you will provide your switch stack with a higher rate of survival due to power issues. 

2021-09-15T17:51:00Z
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