安装好centos系统后，一开始是无法上网的，修改IP地址的方法有很多，但是最规矩的还是修改配置文件。
[root@localhost /]# cd /etc/sysconfig/network-scripts/ [root@localhost network-scripts]# ls ifcfg-eno16777736 ifdown-isdn ifup ifup-plip ifup-tunnel ifcfg-lo ifdown-post ifup-aliases ifup-plusb ifup-wireless ifdown ifdown-ppp ifup-bnep ifup-post init.ipv6-global ifdown-bnep ifdown-routes ifup-eth ifup-ppp network-functions ifdown-eth ifdown-sit ifup-ib ifup-routes network-functions-ipv6 ifdown-ib ifdown-Team ifup-ippp ifup-sit ifdown-ippp ifdown-TeamPort ifup-ipv6 ifup-Team ifdown-ipv6 ifdown-tunnel ifup-isdn ifup-TeamPort [root@localhost network-scripts]#在这个目录下有很多文件，其中ifcfg-enxxxx是我们需要修改的网卡文件。
打开配置文 vi ifcfg-eno16777736
TYPE=Ethernet BOOTPROTO=dhcp DEFROUTE=yes PEERDNS=yes PEERROUTES=yes IPV4_FAILURE_FATAL=no IPV6INIT=yes IPV6_AUTOCONF=yes IPV6_DEFROUTE=yes IPV6_PEERDNS=yes IPV6_PEERROUTES=yes IPV6_FAILURE_FATAL=no NAME=eno16777736 UUID=4f27b78f-c104-49d2-b3e7-c2a691b1619c DEVICE=eno16777736 ONBOOT=no网卡配置文件参数：
DEVICE:网卡名称
HWADDR:物理mac地址
TYPE：网络类型
UUID：网卡唯一标识
ONBOOT：开机或者重启是否重启网卡
NM_CONTROLLED：是否受network程序管理
BOOTPROTO：网卡获取ip地址方式：none dhcp static
IPADDR：设置ip
DATEWAY：设置网关
NETMASK：子网掩码
USERCTL：普通用户是否可以控制网卡
DNS:域名解析服务
设置完成后进行重启网卡的操作
systemctl restart network查看网卡IP地址
[root@localhost network-scripts]# ifconfig eno16777736: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.186.131 netmask 255.255.255.0 broadcast 192.168.186.255 inet6 fe80::20c:29ff:fec9:de0b prefixlen 64 scopeid 0x20<link> ether 00:0c:29:c9:de:0b txqueuelen 1000 (Ethernet) RX packets 14140 bytes 4382696 (4.1 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 6244 bytes 1150905 (1.0 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 0 (Local Loopback) RX packets 4 bytes 352 (352.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 4 bytes 352 (352.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0如果提示没有这个命令，则进行下载即可。
yum install -y net-tools参考： https://blog.csdn.net/m0_38003171/article/details/80672220
