随着宽带技术的快速发展，服务器使用万兆网卡的概率越来越高。最近装了几台服务器都用的万兆网卡，为了图便宜，网卡和模块都是淘宝上买的，这部还真遇到不少问题。
我的服务器都是centos6.4 64位的，网卡装上后，lspci | grep 82599 能看到网卡
执行lspci |grep 82599能看到网卡在pci设备中
04:00.0 Ethernet controller: Intel Corporation 82599ES 10-Gigabit SFI/SFP+ Network Connection (rev 01)
但是ifcfg -a 看不到网卡比如p2p1
使用dmesg | grep ixgbe 发现报错，说发现不支持的光模块，查看intel82599使用手册嘿，里面还真说了，那些网卡经过测试，意思这些默认是支持的。
ixgbe 0000:04:00.0: setting latency timer to 64
ixgbe 0000:04:00.0: failed to load because an unsupported SFP+ module type was detected.
ixgbe 0000:04:00.0: Reload the driver after installing a supported module.
后然搜索发现有篇文章说到光模块兼容性问题，马上试了一下，果然解决了。
rmmod ixgbe 先删除驱动
重新加载驱动，
modprobe ixgbe allow_unsupported_sfp=1,1
驱动对allow_unsupported_sfp的解释为：
allow_unsupported_sfp:Allow unsupported and untested SFP+ modules on 82599-based adapters (uint)，即允
许82599网卡使用不兼容SFP+模块。
重新加载后，大部分情况下ifconfig就能够看到网卡信息了。
另外如果遇到安装驱动等问题，可以参考intel网卡的readme，里面很全面，不过是英文的。
硬件方面注意模块的光波长，单/多模，光纤收发等。默认支持的模块如下：
SFP+ Devices with Pluggable Optics
----------------------------------
82599-BASED ADAPTERS
--------------------
NOTES:
- If your 82599-based Intel(R) Network Adapter came with Intel optics or is an
Intel(R) Ethernet Server Adapter X520-2, then it only supports Intel optics
and/or the direct attach cables listed below.
- When 82599-based SFP+ devices are connected back to back, they should be
set to the same Speed setting via ethtool. Results may vary if you mix
speed settings.
Supplier Type Part Numbers
-------- ---- ------------
SR Modules
Intel DUAL RATE 1G/10G SFP+ SR (bailed) FTLX8571D3BCV-IT
Intel DUAL RATE 1G/10G SFP+ SR (bailed) AFBR-703SDZ-IN2
Intel DUAL RATE 1G/10G SFP+ SR (bailed) AFBR-703SDDZ-IN1
LR Modules
Intel DUAL RATE 1G/10G SFP+ LR (bailed) FTLX1471D3BCV-IT
Intel DUAL RATE 1G/10G SFP+ LR (bailed) AFCT-701SDZ-IN2
Intel DUAL RATE 1G/10G SFP+ LR (bailed) AFCT-701SDDZ-IN1
The following is a list of 3rd party SFP+ modules that have received some
testing. Not all modules are applicable to all devices.
Supplier Type Part Numbers
-------- ---- ------------
Finisar SFP+ SR bailed, 10g single rate FTLX8571D3BCL
Avago SFP+ SR bailed, 10g single rate AFBR-700SDZ
Finisar SFP+ LR bailed, 10g single rate FTLX1471D3BCL
Finisar DUAL RATE 1G/10G SFP+ SR (No Bail) FTLX8571D3QCV-IT
Avago DUAL RATE 1G/10G SFP+ SR (No Bail) AFBR-703SDZ-IN1
Finisar DUAL RATE 1G/10G SFP+ LR (No Bail) FTLX1471D3QCV-IT
Avago DUAL RATE 1G/10G SFP+ LR (No Bail) AFCT-701SDZ-IN1
Finisar 1000BASE-T SFP FCLF8522P2BTL
Avago 1000BASE-T ABCU-5710RZ
HP 1000BASE-SX SFP 453153-001
82599-based adapters support all passive and active limiting direct attach
cables that comply with SFF-8431 v4.1 and SFF-8472 v10.4 specifications.（基于这两个协议的模块都支持）
有一点很奇怪的是，我的光模块是Finisar FTLX1471D3BCL，按道理没有任何问题，有可能这次淘宝上买歪了。
最后感谢这篇文章：http://www.linuxdiyf.com/linux/23173.html