X690 and long distance stacking

[Charles2004]

Hi community 

I have found i user guide that for stacking this switch supports 61 and 69 data ports and also that only QSFP28 DACs with lenght up to 5m can be used .

Does it mean that stacking for longer distances is not supported ?

I would like  to stack two X690 located on two seperated Data Centers with at least 4 x40G links or other.

Is it supported on this model ?

I would appreciate any help

Best regards 

Karol 

[Charles2004]

Hi Stefan 

I just wanted to be sure 

Thank You for answer and fast help 🙂

Best regards

Karol

[Stefan_K_]

Hi Charles,

I see. 🙂 Stacking is of course fine if you are aware of the disadvantages.
Why do you want to use more/other ports than 61/69? These links state that 61 and 69 are the only stacking ports:
https://documentation.extremenetworks.com/summit/GUID-2409A08C-9642-4245-9DB1-D7893DA1662F.shtml

https://documentation.extremenetworks.com/summit/GUID-B257AC27-28E6-4FB6-B785-86BBBB8C34A6.shtml

Best regards
Stefan

[Charles2004]

Hi Nikolay and Stefan

Thank You for your hints and explanations. I would think over about MLAG, I like stacking bacause of simplicity although I know that MLAG has some advantages.

Can I use more ports for stacking then 61 and 69 ?

Regards 

Karol

[Stefan_K_ · Accepted solution]

Well they don’t have “such” an distance limitation, but they do have a limitation, or am I wrong? According to the Datasheet the following maximum lengths apply to AOC cables:

20m for 100G
100m for 40G

A possibility would be SummitStack-V (or Alternate Stacking) but X690 doesn’t support this.

Charles, do you really want to stack theses switches? Personally I don’t like to stack central Datacenter switches (if there is an logical error, the whole stack is affected. And also if you do a firmware upgrade the whole stack will be down)
If you need to create an LAG from another Switch or Server to those X690s, think about MLAG instead of stacking. Just a hint. 🙂

Edit: I have to correct myself: Here it is described that Stacking via QSFP-SR4, LR4, CWDM4 and PSM4 is indeed working. But AOC would still not work over greater distances.

Best regards
Stefan