How do I list network interfaces?
Type the following command:# ip a
Fig.01: List NICs in a CentOS 7 server using ip commandOr use the following command:# nmcli -p dev
Sample outputs:
Fig.02: nmcli command in actionHere is a typical DHCP configration for eth0 (stored in /etc/sysconfig/network-scripts/ifcfg-eth0 file):
DEVICE="eth0" ONBOOT=yes NETBOOT=yes UUID="41171a6f-bce1-44de-8a6e-cf5e782f8bd6" IPV6INIT=yes BOOTPROTO=dhcp HWADDR="00:08:a2:0a:ba:b8" TYPE=Ethernet NAME="eth0"
How do I configure an eth0 interface with static network IP settings (method # 1)?
To configure an eth0 interface with static network settings using ifcfg files, edit or create a file with name ifcfg-eth0 in the /etc/sysconfig/network-scripts/ directory as follows:# vi /etc/sysconfig/network-scripts/ifcfg-eth0
Update/edit as follows for static IP configuration:
# static IP address on CentOS 7 or RHEL 7# HWADDR=00:08:A2:0A:BA:B8 TYPE=Ethernet BOOTPROTO=none # Server IP # IPADDR=192.168.2.203 # Subnet # PREFIX=24 # Set default gateway IP # GATEWAY=192.168.2.254 # Set dns servers # DNS1=192.168.2.254 DNS2=8.8.8.8 DNS3=8.8.4.4 DEFROUTE=yes IPV4_FAILURE_FATAL=no # Disable ipv6 # IPV6INIT=no NAME=eth0 # This is system specific and can be created using 'uuidgen eth0' command # UUID=41171a6f-bce1-44de-8a6e-cf5e782f8bd6 DEVICE=eth0 ONBOOT=yes
Save and close the file. You do not need to specify the network or broadcast address as this is calculated automatically by the system. To restart networking service, enter:# systemctl restart network
Verification
Verify new IP settings:# ip a s eth0
Verify new routing settings:# ip rVerify DNS servers settings:# cat /etc/resolv.conf
Verify the internet connectivity:# ping -c 3 cyberciti.biz
# ping -c 4 google.com
Sample session:
Fig.03: Testing networking and make sure everything is working
How do I configure an eth0 interface with static IP address on CentOS 7 / RHEL 7 using Network Manager (method # 2)?
You need to use the nmtui command. It is a curses?based TUI application for interacting with NetworkManager. To show a connection editor that supports adding, modifying, viewing and deleting connections. To view or setup a static IP using this tool for eth0, enter:# nmtui edit eth0
Sample outputs:
Fig.04: nmtui is a curses?based TUI application for interacting with NetworkManager.