How to configure a Dedibox failover IP on Debian and Ubuntu

This guide provides step-by-step instructions for configuring a Dedibox failover IP on Debian and Ubuntu Linux. A failover IP is a secondary IP address that can be assigned to your server.

Before you startLink to this anchor

To complete the actions presented below, you must have:

• A Dedibox account logged into the console
• Created a Dedibox dedicated server

Failover IP configuration on DebianLink to this anchor

1. Connect to your server using SSH and open the network configuration file /etc/network/interfaces in a text editor, such as nano:

   nano /etc/network/interfaces
   

2. Add the failover IP to the configuration as shown in the following example:

   # This file describes the network interfaces available on your system
   # and how to activate them. For more information, see interfaces(5).
   # The loopback network interface
   auto lo
   iface lo inet loopback
   # The primary network interface
   auto eth0
   iface eth0 inet static
       address 195.154.123.123
       netmask 255.255.255.0
       gateway 195.154.123.1
   auto eth0:0
   iface eth0:0 inet static
       address ip_failover
       netmask 255.255.255.255
   

   Note

   The interface name (eth0 in this example) may vary depending on your OS version and system configuration. Use the ifconfig command to determine the name of your primary network interface.

3. Save the file and exit the editor. Bring up the interface using the following command:

   ifup eth0:0
   

Failover IP configuration on Ubuntu (Netplan)Link to this anchor

Since Ubuntu 18.04, Netplan has been the default network configuration system.

1. Disable cloud-init network configuration to prevent conflicts with Netplan:

   sudo mkdir -p /etc/cloud/cloud.cfg.d
   echo 'network: {config: disabled}' | sudo tee /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg
   

   Important

   This step is necessary to prevent cloud-init from overriding the Netplan configuration.

2. Backup the existing Netplan configuration and create a new file:

   sudo cp /etc/netplan/50-cloud-init.yaml /etc/netplan/01-myplan.yaml
   sudo mv /etc/netplan/50-cloud-init.yaml /etc/netplan/50-cloud-init.yaml-backup
   

3. Edit the new Netplan configuration file /etc/netplan/01-myplan.yaml using nano:

   network:
     renderer: networkd
     ethernets:
       enp5s0:
         critical: true
         dhcp-identifier: mac
         dhcp4: false
         dhcp6: false
         addresses:
           - 51.111.222.333/24  # Server main IP (/24)
           - 212.111.222.333/32  # Alternate IPs / IP redirects (/32)
           - 212.111.222.334/32
           - 212.111.222.335/32
         routes:
           - to: 0.0.0.0/0
             via: 62.210.0.1
             metric: 1
             on-link: true
         nameservers:
           addresses:
             - 51.159.69.156
             - 51.159.69.162
       enp6s0:
         dhcp4: true
         dhcp4-overrides:
           use-routes: false
         routes:
           - to: 10.88.0.0/13  # Use appropriate IP/gateway from DHCP
             via: 10.89.23.129
   version: 2
   

   Tip

   Ensure that indentation and formatting are correct to avoid YAML syntax errors.

4. Run the following command to test the configuration:

   sudo netplan try
   

5. If everything works as expected, apply the configuration:

   sudo netplan apply
   

   Important

   If there is an error in your configuration, it might render your network inaccessible. You may need to revert changes using KVM/IPMI access.

TroubleshootingLink to this anchor

If you encounter issues with your network configuration, check the logs using:

sudo journalctl -u systemd-networkd --no-pager

You can also refer to the official Canonical repository for more Netplan examples and troubleshooting guides.