View IP information

After CentOS is installed, view the ip information through the ip addr command

[root@localhost yum.repos.d]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 08:00:27:39:fe:2b brd ff:ff:ff:ff:ff:ff

View network card configuration

Enter the network card profile directory

cd /etc/sysconfig/network-scripts/

View the catalog file as follows

ifcfg-enp0s3      ifdown       ifdown-ippp ...

It can be seen that the network card configuration file is ifcfg-enp0s3. Some computers may be eth0 or other

Configure dynamic IP

Edit network card profile

vi /etc/sysconfig/network-scripts/ifcfg-enp0s3

The contents of the document are as follows

YPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=dhcp
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=enp0s3
UUID=e7666215-13db-4cc2-bbea-6fd152c7b4a8
DEVICE=enp0s3
ONBOOT=no

Change ONBOOT=no to ONBOOT=yes

...
ONBOOT=yes

service network restart

service network restart
//perhaps
/etc/init.d/network restart

Restart of network service succeeded

Restarting network (via systemctl):                        [  OK  ]

View ip information

At this time, you can see that ip is 192.168.2.107

...
inet 192.168.2.107/24 brd 192.168.2.255 scope global noprefixroute dynamic enp0s3
...

Configure static ip

The above configuration is dynamic ip. When the system is restarted, the ip may change, so you need to configure the ip as static.

Modify profile

Change BOOTPROTO=dhcp to BOOTPROTO=static

...
BOOTPROTO=static
...

Add static ip information

IPADDR=192.168.2.110    // Static ip
GETWAY=192.168.2.1      // default gateway
NETMASK=255.255.255.0   // Subnet mask
DNS1=192.168.2.1        // DNS address

service network restart

service network restart