Elastic IP addresses are static IP addresses designed for dynamic cloud computing. An elastic IP address is associated with your AWS account. With an elastic IP address, you can mask the failure of an instance or software by rapidly remapping the address to another instance in your account.
An elastic IP address is a public IP address that you can allocate to an instance or a network interface. If you associate an elastic IP address with an instance that already has a public IP address, the instance's original public IP address is replaced with the elastic IP address. If you associate an elastic IP address with a network interface, the IP address is associated with the primary private IP address of the network interface.
You can allocate a new elastic IP address while creating an instance using the Amazon EC2 console. You can also allocate a new elastic IP address from your existing pool of elastic IP addresses. You can associate an elastic IP address with an instance or a network interface at any time.
If you disassociate an elastic IP address from an instance, the instance is assigned a new public IP address from the Amazon EC2 pool of public IP addresses. If you disassociate an elastic IP address from a network interface, the primary private IP address of the network interface is reassigned from the elastic IP address to another private IP address from the IP address pool of the subnet.
To allocate an elastic IP address using the Amazon EC2 console
Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Elastic IPs.
Choose Allocate new address.
Choose Allocate.
Choose Close.
Your elastic IP address is now allocated and ready to be associated with an instance or network interface.
To associate an elastic IP address with an instance using the Amazon EC2 console
Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
From the instances list, select the instance.
Choose Actions, Networking, Change Elastic IP Address, Associate Elastic IP Address.
Select the elastic IP address from the list, and then choose Associate.
Your instance is now associated with the elastic IP address.
To associate an elastic IP address with a network interface using the Amazon EC2 console
Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Network Interfaces.
Select the network interface, and then choose Action, Networking, Change Elastic IP Address, Associate Elastic IP Address.
Select the elastic IP address from the list, and then choose Associate.
Your network interface is now associated with the elastic IP address.
To disassociate an elastic IP address from an instance or network interface using the Amazon EC2 console
Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Elastic IPs.
Select the check box next to the elastic IP address that you want to disassociate.
Choose Actions, Networking, Change Elastic IP Address, Disassociate Elastic IP Address.
When prompted for confirmation, choose Yes, Disassociate.
The elastic IP address is now disassociated from the instance or network interface.
You can release an elastic IP address when you no longer need it. To release an elastic IP address using the Amazon EC2 console
Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Elastic IPs.
Select the check box next to the elastic IP address that you want to release.
Choose Actions, Networking, Change Elastic IP Address, Release Elastic IP Address.
When prompted for confirmation, choose Yes, Release.
The elastic IP address is now released and no longer associated with your AWS account.
For more information about elastic IP addresses, see the following: