Finisar FCLF8521P2BTL 1000BASE-T SFP rejected by Intel X710-DA2 despite feature matrix listing
The poster wanted to use a Finisar FCLF8521P2BTL 1000BASE-T copper SFP in an Intel X710-DA2 running NVM 7.1. Intel's X710/XXV710/XL710 Feature Support Matrix (rev. 3.4, Nov 2019, doc 332191-024) lists single-speed SFP 1GBASE-T transceivers with support limited to Finisar FCLF-8521-3, Kinnex A XSFP-T-RJ12-0101-DLL and Avago ABCU-5710RZ, and notes that FCLF8521P2BTL is functionally equivalent to the discontinued FCLF-8521-3. Nevertheless, inserting the module produced "Rx/Tx is disabled on this device because an unsupported SFP module type was detected." The behaviour was reproduced on Ubuntu 18.04 with i40e 2.1.14k and 2.10.19.30 and on ESXi 6.7 U3. Since an FCLF-8521-3 works in an X710-DA4 the poster also runs, they asked what the real support status of 1G SFP modules on X710 adapters is and why Intel documents mention SFP (not SFP+) modules at all if they are unsupported.
- Hardware: Intel X710-DA2, Intel X710-DA4
- Transceivers: Finisar FCLF8521P2BTL, Finisar FCLF-8521-3, Kinnex A XSFP-T-RJ12-0101-DLL, Avago ABCU-5710RZ
- Form factor: SFP
Symptoms / messages:
Rx/Tx is disabled on this device because an unsupported SFP module type was detected.
1G copper SFP rejected on X710-DA2 while FCLF-8521-3 works on X710-DA4
adapter label has no YottaMark sticker and mismatched manufacture dates
Comments 3
Intel support first asked for a photo of the adapter's white label, then stated that the Feature Support Matrix describes the controller silicon and that on the X710 Converged Network Adapter series only the Intel-listed SFP+ SR/LR optics are supported; other brands of modules do not work.
Accepted answer: after examining the label photo, support found inconsistencies (no YottaMark sticker, manufacturing dates that differ between labels) and could not confirm the X710-DA2 is a genuine Intel adapter, suggesting this is why the module is rejected; Intel's YottaMark and product-label articles (000007074, 000007060) were linked for checking authenticity.
The poster stressed that a Finisar FCLF-8521-3 works in their X710-DA4 and began comparing the working DA4 with the failing DA2 to isolate the difference; the details are cut off in the captured page.