Failover IP on Bare Metal Cloud Servers

Failover IP - Overview

Failover IP addresses are additional IP addresses, available for Bare Metal Cloud Servers. They allow you to move an IP from one server to another without changing your whole configuration. Failover IPs can also be used as additional IP addresses to create virtual machines on your Bare Metal Cloud Server.

This documentation provides information on the following topics:

Note: Failover IPs are available only for Bare Metal Cloud Servers and offer different functionalities than reserved IPs on virtual instances.

Requirements

Ordering a Failover IP

1 . Connect yourself to your Scaleway Console

2 . Click on Bare Metal in the Compute section of the side-menu.

3 . The list of your Bare Metal Cloud Servers displays. Click on the Failover IP tab on top of the page to enter the failover IP section of the console:

4 . Click on + Order a failover IP to order a new failover IP.

5 . The order dialog displays. Optionally you can enter a description and tags to facilitate the management of your failover IPs. Tags allow you to filter IP addresses from the Scaleway console. Once done, confirm the order by clicking on Order a failover IP.

6 . The failover IP will be added to the list of your failover IPs:

Allocating a Failover IP

Once you have ordered a failover IP, you can configure it to be allocated to one of your Bare Metal Cloud Servers. For each of your servers, you can order up to 64 failover IPs. The Scaleway Console provides two options to manage your failover IPs:

You can choose your preferred option using the slider button on top of the page.

Allocating a Failover IP using List View

1 . Set the toggle switch to List view. The failover IP displays in the list of your failover IPs:

2 . Click on Add Target to assign the IP to one of your Bare Metal Cloud Servers.

3 . The configuration dialog displays. Choose the Bare Metal Cloud Server to which you want to assign the IP from the drop down list.

4 . Click Validate to confirm the configuration. The failover IP is being allocated to your Bare Metal Cloud Server.

Allocating a Failover IP using Drag and Drop View

1 . Set the toggle switch to Drag and Drop view. The failover IP configuration displays in drag and drop mode:

2 . Drag and drop the failover IP from the Failover IP section to the page to your server in the Bare Metal Cloud Servers section of the page.

3 . The failover IP displays next to your servers name.

4 . Click on Validate to update the configuration and to assign the IP to the server.

Note: If you are using virtual MAC groups, all failover IPs sharing the same MAC address will be moved from one server to another.

Configuring a Failover IP

A failover IP needs to be configured on the Bare Metal Cloud Server to make it reachable.
The configuration depends on the Operating System running on the machine.

Configuring a Failover IP on Ubuntu

On the latest LTS release of Ubuntu (Version 18.04 Bionic Beaver) you can configure the Failover IP using Netplan. If you prefer a more traditional configuration, refer to the Debian section of the documentation.

1 . Edit the file /etc/netplan/01-netcfg.yaml and configure static networking for your server.

2 . IP addresses in the configuration file have to be specified in CIDR notation. The netmask is /24 for the principal IP of the server and /32 for each failover IP.
Your configuration file should look like in the following example:

network:
  version: 2
  renderer: networkd
  ethernets:
    enp1s0f0:
      addresses: [163.172.123.123/24, 212.83.123.123/32]
      gateway4: 163.172.123.1
      nameservers:
        addresses: [ "62.210.16.6", "62.210.16.7" ]

Note: The interface name for your primary interface may be different than enp1s0f0. You can use the ip link show command to determine the name of your public Internet interface.

3 . Save the configuration file once edited as required and quit the text editor. Then apply the configuration using the following command:

sudo netplan apply

Configuring a Failover IP on Debian

1 . Open the file /etc/network/interfaces in your favourite text editor.

2 . Edit the file and add the failover IP 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 of your server might be different depending on the hardware of the server. You can use the ip link show command to determine the name of your public Internet interface.

3 . Save the file and quit the editor.

4 . Bring the interface up using the ifup command:

ifup eth0:0

Configuring a Failover IP on CentOS

1 . Copy the default network configuration file to create an alias:

cp /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth0:0

2 . Open the file /etc/sysconfig/network-scripts/ifcfg-eth0:0 in your favourite text editor and modify it as in the following example:

DEVICE="eth0:0"
BOOTPROTO=static
IPADDR="my_failover_ip"
NETMASK="255.255.255.255"
ONBOOT=yes

3 . Save the file, exit the text editor and run the following command to reload the network configuration:

/etc/init.d/network restart

Changing the Assigned Server

You can update the destination host of a failover IP from the Scaleway Console.

The following steps can be executed either from list or drag and drop view.

1 . Click on next to the failover IP that you want to move to another Bare Metal Cloud Server.

2 . The configuration menu of the failover IP displays. Click on More Info to see detailed information about the IP address.

3 . The IP information page displays. Click on Manage assignment to update the destination of the failover IP:

4 . Choose the new destination host from the drop down list and click on Validate to update the configuration:

Configuring the Reverse DNS

Reverse DNS, or rDNS, is exactly the opposite of classic forward DNS as we know it. Forward DNS maps a hostname to an IP address. Reverse DNS means we are mapping the IP address to a hostname. This can be very useful, especially if you want to send emails from your Bare Metal Cloud Server.

1 . Click on next to the failover IP that you want configure.

2 . The configuration menu of the failover IP displays. Click on More Info to see detailed information about the IP address.

3 . Scroll down to the Reverse section and click on Add Reverse:

4 . Enter the new reverse DNS and click on Edit this reverse to validate the changes.

Note: Make sure that a corresponding A-Record pointing to the IP address exists before editing the reverse DNS of an IP address.

Adding a Virtual MAC Address

Virtual MAC addresses are virtual interface identifiers and are required for virtualization. If you run multiple virtual machines on a physical Bare Metal Cloud Server, you can configure the MAC address of its virtual network interface to the virtual MAC associated to the failover IP to ensure network connectivity of the virtual machine.

Note: Virtual MAC addresses are only required for virtualization purposes. If you want to configure the failover IP as a second interface on the host OS, no virtual MAC is required.

1 . Click on next to the failover IP that you want configure.

2 . The configuration menu of the failover IP displays. Click on More Info to see detailed information about the IP address.

3 . Scroll down to the Mac address section and click on Add Reverse:

4 . Choose the desired type of the virtual MAC address. You can choose from VMware, XEN or KVM. It is recommended to choose the type corresponding to your virtualization technology. Confirm by clicking on Generate MAC Address.

If the virtual MAC address is no longer being needed, you can remove it from the failover IP by clicking on the Delete button.

For more information how to configure the failover IP on a virtual machine, refer to our documentation

Creating Virtual MAC Groups

If you want to assign multiple failover IPs to one virtual machine, you can create virtual MAC groups. A virtual MAC group contains at least two failover IPs that share the same virtual MAC address.
Once the virtual MAC group is active, the IPs sharing the same MAC address are linked together. Moving one IP of the group will move automatically all IPs within the group from one Bare Metal Cloud Server to another.

Note: You need to have at least two failover IPs in your account to create a virtual MAC group.

1 . Make sure that at least one failover IP is assigned to one of your servers.

2 . Drag and drop the second failover IP from the Failover IPs section to your Bare Metal Cloud Server.

3 . Click on > Generate Mac, then select Copy from another failover IP from the drop-down list:

4 . Choose the IP to copy the MAC address from in the list of available IPs and click Generate MAC Address to confirm:

5 . The virtual MAC group is being created. Once ready, the status indicator becomes green.

The IPs are now linked together in a virtual MAC group and share the same virtual MAC address. They can be assigned to the same virtual machine to provide a multi-IP environment. When moving one of the IPs of the group to another server, all other IPs within the group are automatically to the same server.

To remove a failover IP from a virtual MAC group, click on > Generate MAC and generate a new MAC address as described in the Adding a Virtual MAC Address section.

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