Building a stack with 2 MS-425 using QSFP

[NetQloud]

Hi, we're trying to build a stack with two MS425-32 in two DC's over a distance of appr. 400 mtr. using QSFP-40 LC/LC and singlemode fiber.

First we tried using a stack cable of 1mtr. and it works fine, but with the QSFP's and over a larger distance the device won't get connected and show lots of CRC errors. SM fiber is OK, it's new, tested, we even used different fiber pairs. QSFP are brandnew Cisco certified

Anyone having experience on this.

[Brash]

I'll start by suggesting that stacking switches over a large physical distance isn't ideal, but according to the doco it should work. What model of transceiver and type of cabling are you using?

[NetQloud]

Hi Alemabrahao,

We use the QSFP-40G-IR4-SO and the type of cabling is Single Mode fiber with a distance of appr. 400 meter maximum

[Brash]

That QSFP type (IR4) is not supported in Meraki switches. See the below compatibility matrix.

https://documentation.meraki.com/General_Administration/Cross-Platform_Content/SFP_and_Stacking_Acce...

[alemabrahao]

It's a problem. This Qsfp model is not supported.

Take a look at the supported model.

https://meraki.cisco.com/pt-br/product/switches/switches-accessories/switches-accessories-qsfp-plus/...

[NetQloud]

Looks like that indeed. I was given the promise it would work, but I'm going to send the QSFP's back and build a stack with SFP+ instead.

[alemabrahao]

CRC means physical issue.

[JacekJ]

I'm using 4pcs of non Meraki 40G QSFP modules to stack MS425 switches via SM at around 200m distance.

https://gbcphotonics.com/en/qsfp-plus-40g/1443-qsfp-lx4.html

It's at least 2 years now without one issue and never had Meraki support complaining on them during troubleshooting sessions.

Of course according to the datasheet your only option is -> MA-QSFP-40G-LR4

I remember that back then the price was mind blowing so we went for testing the GBC's for a while and headed that way after finding them being just fine.

[NetQloud]

I recognize the problem with pricing. We're gonna check and do some trial and error. Thanks for responding.