检查网卡配置文件是否有误：
例：
vim /etc/sysconfig/network-scripts/ifcfg-em1
TYPE=Ethernet PROXY_METHOD=none BROWSER_ONLY=no BOOTPROTO=static DEFROUTE=yes IPV4_FAILURE_FATAL=no IPV6INIT=yes IPV6_AUTOCONF=yes IPV6_DEFROUTE=yes IPV6_FAILURE_FATAL=no IPV6_ADDR_GEN_MODE=stable-privacy NAME=em1 UUID=dbe366d7-bb88-451e-b449-8a1a1b5e3115 DEVICE=em1 ONBOOT=yes IPADDR=192.168.1.8 GATEWAY=192.168.1.1 NETMASK=255.255.255.0 ZONE=public
vim /etc/resolv.conf
# Generated by NetworkManager nameserver 100.100.2.136 nameserver 100.100.2.138 nameserver 114.114.114.114 nameserver 8.8.8.8 nameserver 192.168.1.1
重启网卡
ifdown em1
ifup em1
重启网络服务
systemctl restart NetworkManager
systemctl restart network
或
service network restart
service NetworkManager restart