Configure a Manual Elastic IP

Manual Elastic IPs require additional configuration on the target instance for that instance to receive traffic.

WARNING
The Elastic IP address is set up as an additional IP address for your instance. The original IP address will still work, as it is used for outgoing connections. Do not remove the original IP address of the instance as the Elastic IP will not work without it. Several other native functionalities will also break.

The operations and commands to be performed vary depending on your chosen template. Below are a few examples for different templates:

Ubuntu

Ubuntu 18.04 LTS (Bionic Beaver)

In /etc/netplan/51-eip.yaml, put the following snippet.

network:
  version: 2
  renderer: networkd
  ethernets:
    lo:
      match:
        name: lo
      addresses:
        - 203.0.113.202/32

And then, apply it: sudo netplan apply

Debian

Debian 11 and Ubuntu 16.04 LTS (Xenial Xerus) or older.

In /etc/network/interfaces.d/eip.cfg, add the following snippet:

    auto lo:1
    iface lo:1 inet static
        address 203.0.113.202/32

Then, use ifup lo:1 to enable the Elastic IP. It will also be enabled automatically on boot. From here, you should be able to ping your instance and any service authorized in the associated security group should be reachable with this Elastic IP as well.

If you need to add any additional Elastic IPs, use lo:2, lo:3, et cetera.

On Debian 8, you have to add source /etc/network/interfaces.d/* in your /etc/network/interfaces.

CoreOS

Create the configuration file for loopback interface /etc/systemd/network/loopback-alias.network, with the following content:

[Match]
Name=lo

[Network]

[Address]
Label=lo:1
Address=203.0.113.202/32

Ensure that systemd-networkd is enable: sudo systemctl enable systemd-networkd.service

To apply the configuration, run sudo systemctl restart systemd-networkd to restart. It will also be enabled automatically on boot. You can now ping the Elastic IP address and any service authorized in the associated Security Group should be reachable with this Elastic IP as well.

You can add multiple loopback Address blocks.

Other Linux Distributions

You can manually add the Elastic IP address on any Linux Instance with the following command:

$ ip addr add 203.0.113.202/32 dev lo

Beware:
this configuration will be lost if you reboot the instance in absence of some custom automation.

OpenBSD

Configure your Elastic IP with this single command:

$ echo inet 203.0.113.202/32 > /etc/hostname.lo1

You can reconfigure your network on the fly with:

$ sh /etc/netstart

Since OpenBSD 6.7, it is now required to enable IP routing. This can be done with the command sysctl:

$ sysctl net.inet.ip.forwarding=1

# To persist the change upon reboot
echo net.inet.ip.forwarding=1 >> /etc/sysctl.conf

Windows

As a first step, we need to install a special driver for the hardware wizard. Open a command line and execute the following command:

hdwwiz

You should get the Add Hardware Wizard:

Click on Next. On the next screen, choose the Install the hardware that I manually select from a list:

Click on Next. On the next screen, choose Network adapters:

Click on Next. On the next screen, choose Microsoft in the list on the left-hand side, then Microsoft KM-TEST Loopback Adapter in the list on the right-hand side:

click on Next, then click on Install.

The following steps will assign the EIP to the Loopback interface and activate IP Forwarding to the relevant interfaces.

NOTE
If you don’t have PowerShell on your instance, please try and install it or let us know about it. We will try and provide a different procedure.

Please open your favorite Windows editor and create a file called EIP.ps with the following content:

# Get the EIP in the format XXX.XXX.XXX.XXX/32 from the cli
param(
[string]$EIP
)
# split the address and its mask
$IPAddress=($EIP -split '/' | Select-Object -First 1)
$Mask=($EIP -split '/' | Select-Object -Last 1)
# query http://metadata.exoscale.com/latest/meta-data/local-ipv4 to get the Public IP
$MyPublicIPAddress=(Invoke-WebRequest metadata.exoscale.com/latest/meta-data/local-ipv4).Content.Trim()
# Rename to Loopback
Get-NetAdapter -InterfaceDescription "Microsoft *" | Rename-NetAdapter -NewName "Loopback"
# Configure the EIP
Get-NetAdapter -Name "Loopback" | New-NetIPAddress -IPAddress $IPAddress -PrefixLength $Mask
# Get the Public interface ifIndex
$PublicInterfaceIndex=(Get-NetIPAddress -AddressFamily IPv4 | Where-Object {$_.IPAddress -match $MyPublicIPAddress} | Select-Object InterfaceIndex)
# Get the Loopback interface ifIndex
$LoopbackInterfaceIndex=(Get-NetIPAddress -AddressFamily IPv4 | Where-Object {$_.IPAddress -match $IPAddress} | Select-Object InterfaceIndex)
# Enable Forwarding
Set-NetIPInterface -ifIndex $PublicInterfaceIndex.InterfaceIndex -Forwarding Enable
Set-NetIPInterface -ifIndex $LoopbackInterfaceIndex.InterfaceIndex -Forwarding Enable
# Print the status after the changes
Get-NetIPInterface -AddressFamily IPv4 | select ifIndex,InterfaceAlias,AddressFamily,ConnectionState,Forwarding | Sort-Object -Property IfIndex | Format-Table

Once the file is created you can now add your EIP as follows:

C:\> EIP.ps 203.0.113.203/32

In the same way you can attach multiple EIPs.