CENTOS 7.2 下设置IP

Centos 服务器下设置内网的IP.

首先,查看网卡,执行命令

ifconfig

会显示出当前服务器网卡数量

em1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
    inet 111.111.111.111  netmask 255.255.255.128  broadcast 111.111.111.111
    inet6 ***  prefixlen 64  scopeid 0x0<global>
    inet6 ***  prefixlen 64  scopeid 0x40<site>
    inet6 ***  prefixlen 64  scopeid 0x20<link>
    ether ***  txqueuelen 1000  (Ethernet)
    RX packets 133303685  bytes 28505343137 (26.5 GiB)
    RX errors 0  dropped 359528  overruns 0  frame 0
    TX packets 5254914  bytes 491093949 (468.3 MiB)
    TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    device interrupt 18

em2: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
                ether ***  txqueuelen 1000  (Ethernet)
                RX packets 60693  bytes 3894479 (3.7 MiB)
                RX errors 0  dropped 0  overruns 0  frame 0
                TX packets 227  bytes 20043 (19.5 KiB)
                TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
                device interrupt 19

em3: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
                ether ***  txqueuelen 1000  (Ethernet)
                RX packets 0  bytes 0 (0.0 B)
                RX errors 0  dropped 0  overruns 0  frame 0
                TX packets 0  bytes 0 (0.0 B)
                TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
                device interrupt 19

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 1  (Local Loopback)
                RX packets 36713  bytes 28535534 (27.2 MiB)
                RX errors 0  dropped 0  overruns 0  frame 0
                TX packets 36713  bytes 28535534 (27.2 MiB)
                TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

解释:

UP 网卡开启状态
RUNNING 网卡网线被接上
MULTICAST 支持组播
MTU  最大传输单元
inet  ip4 地址
inet6  ip6地址
broadcast 广播地址
netmask  子网掩码
RX 表示接收数据包的情况
TX 表示发送数据包的情况
txqueuelen  传输缓存区大小

网卡启动命令

ifconfig em2 up

ifconfig em2 down

可以使用命令,查看当前服务器的外网ip

curl ifconfig.me

例如,结果显示:111.111.111.111 表示当前的网卡em1已被外网使用.

除了lo之外(lo不算),还有三个网卡,em2,em3,em4.

em2 有RUNNING,应该表示当前网卡有线接入.选择em2设置内网.

进入目录

cd /etc/sysconfig/network-scripts/
cp ifcfg-em2 ifcfg-em2.bak  #备份

编辑网卡配置文件

TYPE=Ethernet
BOOTPROTO=static  #默认为dhcp
DEFROUTE=yes
PEERDNS=yes
PEERROUTES=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=no  #如果yes改为no
IPV6_AUTOCONF=no #如果yes改为no
IPV6_DEFROUTE=no   #如果yes改为no
IPV6_PEERDNS=no  #如果yes改为no
IPV6_PEERROUTES=no   #如果yes改为no
IPV6_FAILURE_FATAL=no  #如果yes改为no
NAME=em2
UUID=*******
DEVICE=em2
ONBOOT=yes
IPADDR=192.168.1.111  #ip地址  
NETMACK=255.255.255.0    #网关
DNS1=*****   #dns地址

保存

重启网卡