Adding a Public IPv4 Address on a Linux Server (CentOS 8)

This article explains how to add an additional public IPv4 address on a server where CentOS 8 is installed.

Requirements
  • You have assigned an additional public IPv4 address to your server.

  • You have logged on to the server.

  • To check the existing network connections, enter the following command:
    [root@localhost ~]# nmcli connection show

    The network interfaces are then displayed.

    Example: [root@localhost ~]# nmcli connection show
    NAME              UUID                                  TYPE      DEVICE
    Public_ens192     03da7500-2101-c722-2438-d0d006c28c73  ethernet  ens192

  • To add the additional public IPv4 address to the network interface configuration, enter the following command:
    sudo nmcli con mod Public_NETWORKINTERFACE +ipv4.addresses "ADDITIONAL IPv4 ADDRESS"
    Example:
    sudo nmcli con mod Public_ens192 +ipv4.addresses "123.456.789.12"
    The additional public IPv4 address will now be added to the network interface.

  • Enter the following command to restart the server:
    [root@localhost ~]# sudo reboot
    The SSH connection is interrupted after the command is entered.

  • Log on to the server again.

  • To check if the additional public IPv4 address has been added, type the following command:
    [root@localhost ~]# ip addr
    Then, the additional public IPv4 address is displayed.

    Example: [root@localhost ~]# 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: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
        link/ether 00:50:56:11:18:8f brd ff:ff:ff:ff:ff:ff
        inet 217.160.67.241/32 brd 217.160.67.241 scope global noprefixroute ens192
           valid_lft forever preferred_lft forever
        inet 82.165.68.209/32 brd 82.165.68.209 scope global dynamic noprefixroute ens192
           valid_lft 43082sec preferred_lft 43082sec
        inet6 fe80::250:56ff:fe11:188f/64 scope link noprefixroute
           valid_lft forever preferred_lft forever