Is there a tool available that lets you reprogram the 40G compliance setting on a QSFP-4x10G-LR-S? This module advertises 10G-LR compliance which makes it incompatible with the Intel XL710 controller. Intel tells us that they want to see 40G-LR4 or their controller FW will disable Tx.
FS.com sells a gadget they call FS box which lets you do such stuff on FS modules that they sell as Cisco compatibles.
