Catalyst stacking with only two members

[Plati]

Hi, 

When you set up a stack consisting of only two catalyst switches, 
is it not sufficent with one stack kit in total? 
One stack module in each member, and only one stack cable between them? 

We do not need the redundancy or ring when its only two switches?`
Or what are the advantages of having two per member? 
I understand that it only gets half the bandwith.

[Reza Sharifi]

Hi,

It is sufficient to just use one stacking cable. The second one is for redundancy and more bandwidth, but if don't need either one, one cable is enough.

HTH 

[Joseph W. Doherty]

Ditto.

[Leo Laohoo]

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@Plati wrote:
We do not need the redundancy or ring when its only two switches?`

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How important are the wired clients in this stack?  

That is the most important question to ask in relation to "redundancy".  

The next most important question is:  How many uplinks does this stack have?  

[Plati]

There is about 12 access points connected to each switch. 
And, there is a LAG with LACP set up on SFP+ ports for uplink to core switch. 
I use one SFP+ slot from each of the two stack members here. Te1/1/1 and Te2/1/1. 

[Joseph W. Doherty]

Oh, in that case, you'll really want to consider having the second ring link.

Why?

It's rare, but a single ring link can fail while switch remains active.  In your case, you'll have two active switches acting as the SAME switch, both with more than single homed edge links.

[Leo Laohoo]

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@Plati wrote:
And, there is a LAG with LACP set up on SFP+ ports for uplink to core switch. 
I use one SFP+ slot from each of the two stack members here. Te1/1/1 and Te2/1/1. 

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Wait, wait, wait.  Hold on a minute. 

The stack has TWO (2) uplinks but there is only ONE (1) stacking cable?  

Now think very carefully:  Heard of a scenario called "split brain"?