ubuntu突然网速变慢|ubuntu如何重启网卡

这几天发现一台服务器的速度突然从千兆变成十兆

Settings for enp4s0:
	Supported ports: [ TP ]
	Supported link modes:   10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Full 
	                        2500baseX/Full 
	Supported pause frame use: Symmetric Receive-only
	Supports auto-negotiation: Yes
	Advertised link modes:  10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Full 
	                        2500baseX/Full 
	Advertised pause frame use: Symmetric Receive-only
	Advertised auto-negotiation: Yes
	Speed: 10Mb/s
	Duplex: Full
	Port: Twisted Pair
	PHYAD: 0
	Transceiver: internal
	Auto-negotiation: on
	MDI-X: Unknown
Cannot get wake-on-lan settings: Operation not permitted
	Current message level: 0x00000033 (51)
			       drv probe ifdown ifup
	Link detected: yes

之前也是莫名其妙的出现过这种问题，解决方法就是重启下网卡。

sudo /etc/init.d/networking restart

[ ok ] Restarting networking (via systemctl): networking.service.

再查看网卡就回来了

Settings for enp4s0:
	Supported ports: [ TP ]
	Supported link modes:   10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Full 
	                        2500baseX/Full 
	Supported pause frame use: Symmetric Receive-only
	Supports auto-negotiation: Yes
	Advertised link modes:  10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Full 
	                        2500baseX/Full 
	Advertised pause frame use: Symmetric Receive-only
	Advertised auto-negotiation: Yes
	Speed: 1000Mb/s
	Duplex: Full
	Port: Twisted Pair
	PHYAD: 0
	Transceiver: internal
	Auto-negotiation: on
	MDI-X: Unknown
Cannot get wake-on-lan settings: Operation not permitted
	Current message level: 0x00000033 (51)
			       drv probe ifdown ifup
	Link detected: yes

这个操作基本上不会影响SSH的连接，瞬间就完成了，连接也不会断。