Just a quick Linux hint today. If you put an unsupported SFP+ module into an Intel Corporation 82599EB 10-Gigabit SFI/SFP+ card the corresponding network interface (pXpY or ethX) is removed from the system. The following messages is logged in “/var/log/messages”:
Nov 19 11:07:03 hostname kernel: ixgbe 0000:0f:00.0: failed to load because an unsupported SFP+ module type was detected.
To restore the interface you have to remove and reload the card’s kernel driver. To do so run the following commands as root. Please note that all other ports using this driver are also temporary unavailable during that time. That means that active transmissions will probably fail.
rmmod ixgbe; modprobe ixgbe
Red Hat features a similar issue in their knowledgebase article #275333.