10/25G PCIe NIC Auto negotiation Issue

[Qzattitude]

One of my server has 1 PCIe 10/25G NIC and a OCP 10/25G NIC
Also, I have 25G HPE SFP Transceiver modules. I have following bond setup on Server.

Bond Configuration

I have 2 Uplink Category, one is 10G Switch (Cisco 10G SFP/HPE 10G SFP Transceiver) another one is 25G switch (25G HPE Transceiver)

1. Uplink-25G + 25G SFP = NIC ports Work Fine.
2. Uplinl-25G + 10G SFP = NIC ports Work Fine.
3. Uplink-10G + 10G SFP = NIC ports Work Fine.
4. Uplink-10G + 25G SFP = NIC ports Not working. (with/without autoneg on)
1. On this Scenario, we tried to Set 10G Speed on this NIC (PCIe) from BIOS, but even then its not working giving a 25G SFP. With a 10G SFP module it works fine.

We have used the following SFP Modules,

1. 25G SFP Module Model: HPE 25Gb SFP28 SR 30mm XCVR
2. 10G_Cisco Module Model: SFP-10G-SR
3. 10G_HPE Module Mode: HPE X130 10G SFP+ LC SR Transceiver

Over All Senario:
============

Senario

I need to know, what are the possible ways to use the PCIe 10/25G NIC + 25G SFP Transceiver with auto negotiation, when the Uplink is 10G and Uplink is 25G?

[BPSingh · Accepted solution]

Greetings!

Have you got a chance to check with dual-rate (10/25G) transceivers?
Ideally the single rate HPE 25Gb SFP28 SR module is not backward-compatible with 10Gb speeds

[Qzattitude]

I think this is the possible reason!
But with this single rate 25G SFP Trancsiver it works fine on OCP 10/25G Adapter with uplink of 10G!
Why this works though? any Idea?