Extreme Networks

Charles2004 · ‎09-06-2020

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

Stefan_K_ · ‎09-07-2020

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

View solution in original post

Necheporenko__N · ‎09-07-2020

Hello Karol,

That 5m limitation is related to passive DAC cables, in your case you need to use active optic cables (AOC) which don’t have such distance limitation.

Best Regards,

Nikolay

Extreme Networks

X690 and long distance stacking

X690 and long distance stacking