Categories: CentosCentos 7

How to Setup network on centos 7

After installing Centos 7, You may not able to connect network in that machine. This will happen because Ethernet interfaces are not enabled by default.This guide will help you to setup network on centos 7 .
This guide contains network configuration steps both in GUI and command mode.

Setup network on centos 7

let’s start, Type “nmcli d” command in your terminal for quick identification of Ethernet cards installed in your machine.

Here we have 2 interfaces named “enp0s17” and “enp0s18” . it might be different in your case ( Eg: em1 or p4p1 ).

GUI Mode

Recommended for beginners
Step 1 » Type this command “nmtui” to open Network manager and press enter after choosing ” Edit a connection” ( Use TAB for choosing options ) .

Step 2 » Now you can see all network interfaces, choose one and click “Edit“.

» DHCP configuration

Step 3 » For DHCP,
1. Choose “Automatic” in IPv4 CONFIGURATION.
2. Choose Automatic Connect check box.
3. Press OK and quit Network manager.

Now Restart network service by typing below command.
systemctl restart network Now your server will get IP Address from DHCP .

» Static configuration

Step 4 » For manual IP address,
1. Choose “Manual” in IPv4 CONFIGURATION.
2. Add IP Address with Subnet , Gateway and DNS server ( Refer below image ).
3. Choose Automatic Connect check box.
4. Press OK and quit Network manager.

Now Restart network service by typing below command.
systemctl restart network That’s it, Interface will have static IP.

Command Mode

Step 1 » Network interface config files are located in /etc/sysconfig/network-scripts/ directory. Open ifcfg-enp0s17 file ( For interface enp0s17 ) and you can see the content like below.
[root@krizna ~]# vi /etc/sysconfig/network-scripts/ifcfg-enp0s17 TYPE=Ethernet BOOTPROTO=none DEFROUTE=yes IPV4_FAILURE_FATAL=no IPV6INIT=yes IPV6_AUTOCONF=yes IPV6_DEFROUTE=yes IPV6_FAILURE_FATAL=no NAME=enp0s17 UUID=7f1aff2d-b154-4436-9497-e3a4dedddcef ONBOOT=no HWADDR=00:0C:29:A1:B5:D6 PEERDNS=yes PEERROUTES=yes IPV6_PEERDNS=yes IPV6_PEERROUTES=yes

» DHCP configuration

Step 2 » For DHCP
Find the below lines in config File.
BOOTPROTO=none ONBOOT=no and replace with
BOOTPROTO=dhcp ONBOOT=yesNow Restart network service by typing below command.
systemctl restart network Now your server will get IP Address from DHCP

» Static configuration

Step 3 » For Static IP.
Find the below lines in config File.
BOOTPROTO=none ONBOOT=no and replace with
BOOTPROTO=static ONBOOT=yes And add the below lines at the end of the file.
IPADDR=172.27.0.32 NETMASK=255.255.255.0 GATEWAY=172.27.0.1 DNS1=172.27.0.5File will look like below after changes.
TYPE=Ethernet BOOTPROTO=static DEFROUTE=yes IPV4_FAILURE_FATAL=no IPV6INIT=yes IPV6_AUTOCONF=yes IPV6_DEFROUTE=yes IPV6_FAILURE_FATAL=no NAME=enp0s17 UUID=f0c5b37d-299a-43cb-b74b-618bb252d129 ONBOOT=yes HWADDR=00:0C:29:A1:B5:CC IPV6_PEERDNS=yes IPV6_PEERROUTES=yes IPADDR=192.168.1.10 NETMASK=255.255.255.0 GATEWAY=192.168.1.1 DNS1=192.168.1.5
Now Restart network service by typing below command.
systemctl restart networkNow Interface will have static IP.
Additionally you can use /etc/sysconfig/network file for hostname and DNS .
HOSTNAME=server.krizna.com DNS1=192.168.1.5 DNS2=8.8.8.8 SEARCH=krizna.com