Removing a public IPv4 address from a VPS or a migrated Cloud Server (Debian 11)

For VPS and migrated Cloud Servers with Debian 11 installed without Netplan, which are managed in the Cloud Panel

This article explains how to remove an additional public IPv4 address from a VPS or a migrated Cloud Server with Debian 11 installed.

Requirement

You have cancelled the assignment of the additional public IPv4 or IPv6 address in Cloud Panel.

Log in to the server.
Open the etc/systemd/network folder. Enter the following command:
root@debian:~# cd /etc/systemd/network
To check whether there is already a configuration file in this directory, enter the following command:
[root@localhost ~]# ls /etc/netplan
Open the .network file for your network interface with the vi editor.
[root@localhost ~]# vi /etc/systemd/network/10-NETWORK_INTERFACE.network
Example:
[root@localhost ~]# vi /etc/systemd/network/10-ens6.network

Note

The vi editor has an insert mode and a command mode. You can call up insert mode with the [i] key. In this mode, the characters entered are immediately inserted into the text. To call up command mode, press [ESC]. If you use command mode, your keyboard input is interpreted as a command.

In the [Network] section, remove the entry that contains the configuration for the additional IPv4 address. In the example below, the IPv4 address 74.208.98.26 must be removed.
[Network]
Address=74.208.61.32/24
Gateway=74.208.61.1
DNS=212.227.123.16,212.227.123.1

# Additional IPv4 address
Address=74.208.98.26/24
To exit vi and save the file, enter the command :wq and then press Enter.
To restart the systemd-networkd, enter the following command:
[root@localhost ~]# sudo systemctl restart systemd-networkd
To check whether the desired IPv4 and IPv6 addresses have been configured correctly, enter the command ip addr show:
[root@localhost ~]# ip addr