Ubutun重启网卡
一、network
利用root帐户
# service networking restart
利用root帐户
# service networking restart
或者/etc/init.d/networking restart
二、ifdown/ifup
# ifdown eth0
# ifup eth0
三、ifconfig
# ifconfig eth0 down
# ifconfig eth0 up
Ubuntu14.04修改配置，重启网卡没有生效，出现如下问题：
service networking restart //重启网络服务
stop: Job failed while stopping
start: Job is already running: networking
stop: Job failed while stopping
start: Job is already running: networking
tail -f /var/log/upstart/networking.log //查看错误日志
Stopping or restarting the networking job is notsupported.
Use ifdown & ifup to reconfigure desired interface.
Stopping or restarting the networking job is notsupported.
Use ifdown & ifup to reconfigure desired interface.
从以上日志内容可以看出，传统的service重启和停止网络已经不再支持了，需要通过使用ifdown &ifup来实现相应的操作。
重启指定网卡
ifdown eth0 && ifup eth0
