Hello,
we just purchased a bunch of Intel E810-XXVDA2 25G LAN-Adapters (2x SFP28).
With none these adapter we can get a link up on 25G to our Arista DCS-7050CX3M-32S switches (we tried with two different switches).
To connect we use QSFP28 to 4xSFP28 break-out cables from fs.com (https://www.fs.com/de/products/50498.html?attribute=10307&id=199026).
1) We also successfully use these cables with other endpoints (e.g. Mikrotik CCR).
2) When we switch out the break-out cable for a 4x10G one (https://www.fs.com/de/products/36217.html?attribute=9406&id=189594) the connection comes right up (at 10G).
3) We updated the firmware on the NICs to 4.3.0 (and also run the latest 4.30.3M release on the Arista devices)
4) Operating system is Ubuntu 22.04 LTS and we also tried different FEC settings, but with no success.
5) There are zero errors logged on either the Arista or the systems with your NICs, so no indication of what could be the issue.
I found lots of reports of interoperability issues with the E810 at 25G, but apart from maybe some FEC auto-detection issue, we did not find any ideas for our setup and I took the liberty to open this thread.
Running Arista, fs.com cables and Intel E810 NICS seems not really exotic and I hope you agree that this deserves some analysis.
Please let me know if you require any more info.
