If you don’t have a UI on your CentOS system, you need to configure your network via command line. Below are the steps.

You can check your network devices by ip command. Run ip addr, you will get output like below:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
    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: eno16777736: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:cc:c7:57 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.219/24 brd 192.168.0.255 scope global dynamic eno16777736
       valid_lft 31826sec preferred_lft 31826sec
    inet6 fe80::20c:29ff:fecc:c757/64 scope link
       valid_lft forever preferred_lft forever

Network interface config files are located in /etc/sysconfig/network-scripts/ directory. There are segregated files in this folder for all your network devices e.g. ifcfg-en16777736

DHCP

Make sure below lines are in the config file:

BOOTPROTO="dhcp"
ONBOOT="yes"

And file will look like below after changes: 

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="fb0f101a-6299-4179-8cd9-de054cb7b577"
DEVICE="eno16777736"
ONBOOT="yes"

Static IP

Change BOOTPROTO to static

BOOTPROTO="static"

And add below lines at the end of the file

IPADDR=192.168.1.33
NETMASK=255.255.255.0
GATEWAY=192.168.1.1

The file will look like below after changes:

TYPE="Ethernet"
BOOTPROTO="static"
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="fb0f101a-6299-4179-8cd9-de054cb7b577"
DEVICE="eno16777736"
ONBOOT="yes"
IPADDR=192.168.1.33
NETMASK=255.255.255.0
GATEWAY=192.168.1.1

Default gateway can be configured in /etc/sysconfig/network

NETWORKING=yes
HOSTNAME=centos7
GATEWAY=192.168.1.1

DNS

Add below to /etc/resolv.conf

nameserver 8.8.8.8 #Primary DNS
nameserver 8.8.4.4 #Secondary DNS

Hostname

There are several ways to set up hostname

  • Use hostnamectl

    hostnamectl set-hostname centos [--pretty][--static][--transient]

    The name “centos” is persisted to /etc/hostname

  • For internal networking

    Change the IP -> hostname mapping in /etc/hosts

  • Run hostname command

    hostname centos

    Note: This is not persistent

For all steps run systemctl restart network to let the change take effect.