'The problem that we are having with these 10Gb NICs is that they do not come online unless a 1Gb NIC in the same system comes online as well. I'm seeing this behavior in Redhat 5.x, Redhat 6.x, and Windows Server 2012 on this new batch of NIcs that we purchased. This does not happen on some older (1 year old) X520-DA2 NICs that we have, hence my request to downgrade the firmware.
The NICs in question are all being used in Dell Poweredge R610 servers, in PCIe x8 slots. I've already tried switching PCI slots as well, to no avail.
I will try upgrading the driver in Redhat, but I don't think that's it because our existing 10Gb NICs (same exact model, just 1 year old) are using the same driver, same optics, etc. and they work great. Besides, the issue persists across multiple operating systems so I'm inclined to
think it's definitely not a driver issue.
Again, it should be noted that the NICs work fine, once another NIC (in this case, an onboard 1Gb NIC) is activated. We are seeing this across the different operating systems as well.