用ethtool改变网络接口速度是行不通的。

Question

我使用的是具有Gbps以太网卡的lenevo M5服务器，但奇怪的是，当我读取cat /sys/class/net/eth3 3/速时，它同样显示100 Gbps的only.The输出，dmesg和ethtool的输出在下面。你知不知道为什么

root@server1:~# dmesg |grep eth1
[ 3.027487] tg3 0000:16:00.1 eth1: Tigon3 [partno(BCM95769) rev 5719001] (PCI Express) MAC address 08:94:ef:5d:81:a2
[ 3.027497] tg3 0000:16:00.1 eth1: attached PHY is 5719C (10/100/1000Base-T Ethernet) (WireSpeed[1], EEE[1])
[ 3.027503] tg3 0000:16:00.1 eth1: RXcsums[1] LinkChgREG[0] MIirq[0] ASF[1] TSOcap[1]
[ 3.027508] tg3 0000:16:00.1 eth1: dma_rwctrl[00000001] dma_mask[64-bit]
[ 28.133071] bond0: Adding slave eth1
[ 28.249876] bond0: Enslaving eth1 as a backup interface with an up link
[ 53.149602] tg3 0000:16:00.1 eth1: Link is up at 100 Mbps, full duplex
[ 53.149620] tg3 0000:16:00.1 eth1: Flow control is off for TX and off for RX
[ 53.149624] tg3 0000:16:00.1 eth1: EEE is disabled

ethtool eth3

Settings for eth3: 
Supported ports: [ TP ] 
Supported link modes: 10baseT/Half 10baseT/Full 
100baseT/Half 100baseT/Full 
1000baseT/Half 1000baseT/Full 
Supported pause frame use: No 
Supports auto-negotiation: Yes 
Advertised link modes: 100baseT/Full 
Advertised pause frame use: Symmetric 
Advertised auto-negotiation: Yes 
Link partner advertised link modes: 100baseT/Half 100baseT/Full 
1000baseT/Full 
Link partner advertised pause frame use: No 
Link partner advertised auto-negotiation: Yes 
Speed: 100Mb/s 
Duplex: Full 
Port: Twisted Pair 
PHYAD: 2 
Transceiver: internal 
Auto-negotiation: on 
MDI-X: off 
Supports Wake-on: g 
Wake-on: g 
Current message level: 0x000000ff (255) 
drv probe link timer ifdown ifup rx_err tx_err 
Link detected: yes 

当我试图用ethtool -s eth3 speed 1000 duplex full更改速度时，“速度”部分是“未知的”，类似地，文件/sys/class/net/eth3/speed给出了无效的参数。

Answer 1

多亏了“钻石”。经过更多的挖掘，电缆连接服务器的eth端口似乎出现了故障，更换它解决了问题。

Answer 2

检查路由器上该特定端口的端口速度配置，它可能限制在100 that，或者可能自动协商失败，在这种情况下，您可以将其修正为1000 that。

这些命令取决于您的路由器，这里是一个思科示例。