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Adding public IPv4 and IPv6 addresses to a Cloud Server, migrated Cloud Server, or VPS+ (Debian 11)

Valid for Cloud Servers, migrated Cloud Servers, and VPS+ with Debian 11 (without Netplan).

This article explains how to add additional public IPv4 and IPv6 addresses to a Cloud Server, a migrated Cloud Server, or a VPS+ running Debian 11.

Note

How you can establish an encrypted network connection to your server using Secure Shell (SSH) is explained in the following articles:

Establishing an SSH connection to your Linux server on a computer with Microsoft Windows

Establishing an SSH connection to your Linux server on a Linux computer

Please Note

This guide is valid only for Cloud Servers, migrated Cloud Servers, and VPS+. How to add IPv4 and IPv6 addresses to a Dedicated Server is described in the following articles:

Adding a public IPv4 address to an Dedicated Server (Ubuntu 20.04)
Adding a public IPv6 address on a Dedicated Server (Ubuntu 20.04)
Adding a public IPv4 address on a Dedicated Server (Ubuntu 18.04 and Debian 9)
Add public IPv6 address on a Dedicated Server (Ubuntu 18.04 and Debian 9)
Add public IPv4 address on a Dedicated Server (Debian 10)
Adding a public IPv6 address on a Dedicated Server (Debian 10)

How to configure IPv4 addresses and IPv6 addresses on a Cloud Server on which Ubuntu 22.04 with netplan is installed is described in the following article:

Configuring public IPv4 and IPv6 addresses on a Linux server with netplan (Ubuntu 22.04)

Requirements
  • You have assigned one or more additional, public IPv4 and/or IPv6 addresses to your server in the Cloud Panel.
  • You have logged in to the server.
  • You have noted the IPv4 addresses and IPv6 addresses of the server.

Determine network interface

To determine the file name of the network interface, enter the following command:

[root@localhost ~]# ip addr

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 00:50:56:2b:2c:68 brd ff:ff:ff:ff:ff:ff:ff
inet 212.227.209.26/32 brd 212.227.209.26 scope global dynamic ens192
valid_lft 33737sec preferred_lft 33737sec
inet6 fe80::250:56ff:fe2b:2c68/64 scope link
valid_lft forever preferred_lft forever

In this example, the name of the network interface is ens192.

Display gateway for IPv4 and IPv6

  • To display the default gateway of the active interface, enter the following commands:

    IPv4:

    [root@localhost ~]# ip route show | grep 'default'

    IPv6:

    [root@localhost ~]# ip -6 route show | grep 'default'

  • Note the IP addresses of the gateways. These are listed directly after the default via part. Examples:

    IPv4 Gateway

    [root@localhost ~]# ip route show | grep 'default'
    default via 10.255.255.1 dev ens192 proto dhcp src 82.165.247.234 metric 100


    IPv6 gateway

    Cloud Server

    [root@localhost ~]# ip -6 route show | grep 'default'

    Example:

    [root@localhost ~]# ip -6 route show | grep 'default'
    default via fe80::1 dev ens192 proto ra metric 100 expires 4sec pref high

    In this example, fe80::1 is the IPv6 gateway.

    Migrated Cloud Server:

    root@debian:~# ip -6 route show

    Example:

    root@debian:~# ip -6 route show
    ::1 dev lo proto kernel metric 256 pref medium
    fe80::/64 dev ens6 proto kernel metric 256 pref medium

Show default DNS server

To display the DNS servers used, enter the following command:

[root@localhost ~]# resolvectl --no-pager |grep Server

The DNS servers used are then displayed at the end of the output.

Example:

[root@localhost ~]# resolvectl --no-pager |grep Server
Current DNS Server: 212.227.123.16
DNS Servers: 212.227.123.16 212.227.123.17

Make a note of the DNS servers.

Show default DNS server (migrated Cloud Server and VPS+)

If the DNS servers used are not displayed after entering the command, enter the following command:

[root@localhost ~]# cat /var/lib/dhcp/dhclient.NAME_OF_NETWORK_INTERFACE.leases

Example:

cat /var/lib/dhcp/dhclient.ens6.leases

The DNS servers used are then displayed. Example:

lease {
 interface "ens6";
 fixed-address 74.208.61.32;
 option subnet-mask 255.255.255.255;
 option routers 74.208.61.1;
 option dhcp-lease-time 600;
 option dhcp-message-type 5;
 option domain-name-servers 212.227.123.16,212.227.123.17;
 option dhcp-server-identifier 169.254.0.2;
 option host-name "my-server-1";
 renew 5 2024/11/15 12:14:51;
 rebind 5 2024/11/15 12:19:10;
 expire 5 2024/11/15 12:20:25;

Add IPv4 and IPv6 addresses

  • Create a .network file for your network interface using the vi editor. Example:

    [root@localhost ~]# vi /etc/systemd/network/10-ens6.network

  • Insert the following information and replace the placeholders:

    [Match]
    Name=NETWORK_INTERFACE

    [Network]
    Address=MAIN_IPV4_ADDRESS/24
    Gateway=IPV4-GATEWAY
    DNS=IP_ADDRESS_OF_NAMESERVER_1

    # Additional IPv4 address
    Address=ADDITIONAL_IPV4_ADDRESS/24

    # IPv6 configuration
    Address=MAIN_IPV6_ADDRESS/64
    Gateway=IPV6_GATEWAY

    # Additional IPv6 address
    Address=ADDITIONAL_IPV6_ADDRESS/64

    Example:

    [Match] 
    Name=ens6

    [Network]
    Address=74.208.61.32/24
    Gateway=74.208.61.1
    DNS=212.227.123.16,212.227.123.17

    # Additional IPv4 address
    Address=74.208.98.26/24

    # IPv6 configuration
    Address=2001:db8::c0a8:1/64
    Gateway=fe80::1

    # Additional IPv6 address
    Address=2001:db8::c0a8:2/64

Edit hosts file

  • To determine the correct hostname, enter the following command:

    [root@localhost ~]# hostname

  • Open the hosts file with the vi editor. To do this, enter the following command:

    [root@localhost ~]# vi /etc/hosts

  • Insert the following line with the correct hostname:

    127.0.1.1 HOSTNAME

    Example:

    127.0.1.1 debian

  • Press the [ESC] key.
  • To save the change, enter the command :wq.

Restart server and check configuration

  • To restart 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

Note

If the server is no longer accessible due to a configuration error, you can log in to the server using the KVM console and correct the configuration. You can find instructions on how to do this in the following article:

Using the KVM console for server access

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