Solved: Maximum number of 3750 switches that can be stacked

ranjipremandrewp · ‎08-14-2015

What is the maximum number of 3750 switches that can be stacked?

Joseph W. Doherty · ‎08-14-2015

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As Mark has noted, up to nine units. If using the 3750X, as Shaps has noted, you can connect up to 4 units into a power stack, but you can, I believe, have more than one power group per (data) stack. (I also recall, you can have up to nine units connect to the same RPS.)

As Karsten has noted, there are reasons you might not want to stack up to the max. Large stacks are "slow" at the command line. Also, if using StackWise (not StackWisePlus) 3750s, remember all stack members put ALL their traffic on the stack ring and it's also removed by the source stack member. StackWise will load up "faster" than StackWisePlus, and physically, it's only half the bandwidth too.

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Mark Malone · ‎08-14-2015

9 altogether but most people usually just stack up to 6, I have heard of issues with different features once you go past that and problems with the stacking themselves depending on platform an ios version

shaps · ‎08-14-2015

another point to consider is the power stacking can only go up to 4, from what I remember

Karsten Iwen · ‎08-14-2015

These (and many more) questions can be answered by looking at the documentation:

http://www.cisco.com/c/en/us/products/collateral/switches/catalyst-3750-series-switches/prod_qas09186a00801b0971.html

Today, I typically don't stack more then two (sometimes four) devices together. With that you can still build multi-chassis Etherchannels but you limit your failure-domains. Some years ago I liked the idea of configuring hundreds of ports through a single session. But if you have a bug or other problem with the stacking itself, it's possible that you lose all your ports at once. I had to learn this the hard way ...

Joseph W. Doherty · ‎08-14-2015