Sinon, ce qui m'étonne dans une carte avec des cages SFP+, c'est que sans SFP+ le lien est considéré comme ok en direct attach alors que je n'ai rien mis dans la cage :
SFP + avec une carte Intel Corporation 82599ES 10-Gigabit SFI/SFP+ Network Connection (rev 01) :
$ dmesg | grep ixgbe
[    3.207176] ixgbe: Intel(R) 10 Gigabit PCI Express Network Driver - version 4.0.1-k
[    3.221897] ixgbe: Copyright (c) 1999-2014 Intel Corporation.
[    3.407951] ixgbe 0000:01:00.0: Multiqueue Enabled: Rx Queue count = 8, Tx Queue count = 8
[    3.408175] ixgbe 0000:01:00.0: PCI Express bandwidth of 32GT/s available
[    3.408190] ixgbe 0000:01:00.0: (Speed:5.0GT/s, Width: x8, Encoding Loss:20%)
[    3.408305] ixgbe 0000:01:00.0: MAC: 2, PHY: 18, SFP+: 5, PBA No: E66560-005
[    3.408317] ixgbe 0000:01:00.0: 90:e2:ba:19:f7:50
[    3.422525] ixgbe 0000:01:00.0: Intel(R) 10 Gigabit Network Connection
[    4.571968] ixgbe 0000:01:00.1: Multiqueue Enabled: Rx Queue count = 8, Tx Queue count = 8
[    4.589804] ixgbe 0000:01:00.1: PCI Express bandwidth of 32GT/s available
[    4.598945] ixgbe 0000:01:00.1: (Speed:5.0GT/s, Width: x8, Encoding Loss:20%)
[    4.608450] ixgbe 0000:01:00.1: MAC: 2, PHY: 1, PBA No: E66560-005
[    4.617403] ixgbe 0000:01:00.1: 90:e2:ba:19:f7:51
[    4.626857] ixgbe 0000:01:00.1: Intel(R) 10 Gigabit Network Connection
[    4.639489] ixgbe 0000:01:00.0 p1p1: renamed from eth0
[    4.657241] ixgbe 0000:01:00.1 p1p2: renamed from eth1
[   12.715244] ixgbe 0000:01:00.0: registered PHC device on p1p1
[   12.877320] ixgbe 0000:01:00.0 p1p1: detected SFP+: 5
[   13.132163] ixgbe 0000:01:00.0 p1p1: NIC Link is Up 10 Gbps, Flow Control: RX/TX
[  196.588395] ixgbe 0000:01:00.0 p1p1: NIC Link is Down
[  197.843582] ixgbe 0000:01:00.0 p1p1: NIC Link is Up 10 Gbps, Flow Control: RX/TX
10Gbase-T : Avec une carte "Intel Corporation Ethernet Controller 10-Gigabit X540-AT2 (rev 01)" :
$ dmesg | grep ixgbe
[    2.341867] ixgbe: Intel(R) 10 Gigabit PCI Express Network Driver - version 4.0.1-k
[    2.346498] ixgbe: Copyright (c) 1999-2014 Intel Corporation.
[    2.664894] ixgbe 0000:08:00.0: Multiqueue Enabled: Rx Queue count = 8, Tx Queue count = 8
[    2.725862] ixgbe 0000:08:00.0: PCI Express bandwidth of 32GT/s available
[    2.731996] ixgbe 0000:08:00.0: (Speed:5.0GT/s, Width: x8, Encoding Loss:20%)
[    2.898573] ixgbe 0000:08:00.0: MAC: 3, PHY: 0, PBA No: G54042-005
[    2.904420] ixgbe 0000:08:00.0: a0:36:9f:31:50:6e
[    3.164002] ixgbe 0000:08:00.0: Intel(R) 10 Gigabit Network Connection
[    3.550195] ixgbe 0000:08:00.0 p2p1: renamed from eth0
[    8.956142] ixgbe 0000:08:00.0: registered PHC device on p2p1
[   14.865953] ixgbe 0000:08:00.0 p2p1: NIC Link is Up 10 Gbps, Flow Control: RX/TX