我遇到了一个奇怪的问题。在两个不同的操作系统（XenServer7.* 和 centOS7.3）上，有相同的卡、相同的驱动程序和相同更新版本的 ethtool。
如果我在卡上运行 centOS ethtool，我会得到：
Supported ports: [ FIBRE Backplane ]
Supported link modes: 1000baseKX/Full
10000baseKR/Full
40000baseKR4/Full
40000baseCR4/Full
40000baseSR4/Full
40000baseLR4/Full
56000baseKR4/Full
100000baseKR4/Full
100000baseSR4/Full
100000baseCR4/Full
100000baseLR4_ER4/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: Yes
Advertised link modes: 1000baseKX/Full
10000baseKR/Full
40000baseKR4/Full
40000baseCR4/Full
40000baseSR4/Full
40000baseLR4/Full
56000baseKR4/Full
100000baseKR4/Full
100000baseSR4/Full
100000baseCR4/Full
100000baseLR4_ER4/Full
但如果我在 XenServer 上运行相同的命令，我会得到：
Supported ports: [ FIBRE ]
Supported link modes: 1000baseT/Full
1000baseKX/Full
10000baseKR/Full
40000baseKR4/Full
40000baseCR4/Full
40000baseSR4/Full
40000baseLR4/Full
56000baseKR4/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: Yes
Advertised link modes: 1000baseT/Full
1000baseKX/Full
10000baseKR/Full
40000baseKR4/Full
40000baseCR4/Full
40000baseSR4/Full
40000baseLR4/Full
56000baseKR4/Full
这56000baseKR4/完整版出现链接模式仅有的升级 ethtool 后。但是似乎 XenServer 无法看到以下广告方法：
100000baseKR4/Full
100000baseSR4/Full
100000baseCR4/Full
100000baseLR4_ER4/Full
我已经检查了网卡上的 ethtool 和固件。它们与 centOS 中的相同，但 XenServer 不会宣传 100000 链接模式。