25GB link between HX220C-M6S Hyperflex server and Catalyst 9500

[bouazzaoui]

Hi Guys,

the 25G link between Core Stack C9500 and hypeflex node HX220C-M6S did not come up . The 25GBASE Cable 3  is totally working. I have checked the ports from Hyperflex and C9500 , everything is fine.

I May have read somowhere that this issue is related to FEC config . Both ports need to be on cl74. I appreciate if you can help me. 

Thanks

[M02@rt37]

Hello @bouazzaoui,

It's possible that the issue is related to FEC configuration.

Double-check that the FEC configuration on both ends is consistent. Make sure both ports are set to use the same FEC mode.

Do you observe any FEC errors or abnormalities in the statistics, it indicates that there might be an issue with FEC on that particular interface ?

As I concerned, I do enable FEC on the ports and use the cl74 FEC mode. This mode provides a stronger error correction capability and can help stabilize the link.