just wanted to let you know that there's a huge bug, using the CSS610-8G-2S+IN with an Intel X520-DA2.
The Switch will show an active Link on SFP+, but it doesnt get recognized by the Intel NIC, for both and DAC. Reproduced it with 2 different Intel Cards as well as 3 Transceiver pairs and cables and one DAC.
Tried following Firmwares:
2.12 (shipped with this)
With 2.13rc12 the issue is resolved, and i have a stable connection, but when updating to 2.13rc25 the issue is back. So there's definitly a bug in the firmware.
I already created a ticket for this issue, but as it did take me weeks to resolve this, i wanted to share incase someone has the same problem.