Elastic IP addresses - Amazon Virtual Private Cloud

Elastic IP addresses

An Elastic IP address is a static, public IPv4 address designed for dynamic cloud computing. You can associate an Elastic IP address with any instance or network interface in any VPC in your account. With an Elastic IP address, you can mask the failure of an instance by rapidly remapping the address to another instance in your VPC.

Elastic IP address concepts and rules

To use an Elastic IP address, you first allocate it for use in your account. Then, you can associate it with an instance or network interface in your VPC. Your Elastic IP address remains allocated to your AWS account until you explicitly release it.

An Elastic IP address is a property of a network interface. You can associate an Elastic IP address with an instance by updating the network interface attached to the instance. The advantage of associating the Elastic IP address with the network interface instead of directly with the instance is that you can move all the attributes of the network interface from one instance to another in a single step. For more information, see Elastic network interfaces in the Amazon EC2 User Guide for Linux Instances.

The following rules apply:

  • An Elastic IP address can be associated with a single instance or network interface at a time.

  • You can move an Elastic IP address from one instance or network interface to another.

  • If you associate an Elastic IP address with the eth0 network interface of your instance, its current public IPv4 address (if it had one) is released to the EC2-VPC public IP address pool. If you disassociate the Elastic IP address, the eth0 network interface is automatically assigned a new public IPv4 address within a few minutes. This doesn't apply if you've attached a second network interface to your instance.

  • To ensure efficient use of Elastic IP addresses, we impose a small hourly charge when they aren't associated with a running instance, or when they are associated with a stopped instance or an unattached network interface. While your instance is running, you aren't charged for one Elastic IP address associated with the instance, but you are charged for any additional Elastic IP addresses associated with the instance. For more information, see Amazon EC2 Pricing.

  • You're limited to five Elastic IP addresses. To help conserve them, you can use a NAT device. For more information, see NAT devices for your VPC.

  • Elastic IP addresses for IPv6 are not supported.

  • You can tag an Elastic IP address that's allocated for use in a VPC, however, cost allocation tags are not supported. If you recover an Elastic IP address, tags are not recovered.

  • You can access an Elastic IP address from the internet when the security group and network ACL allow traffic from the source IP address. The reply traffic from within the VPC back to the internet requires an internet gateway. For more information, see Security groups for your VPC and Network ACLs.

  • You can use any of the following options for the Elastic IP addresses:

    • Have Amazon provide the Elastic IP addresses. When you select this option, you can associate the Elastic IP addresses with a network border group. This is the location from which we advertise the CIDR block. Setting the network border group limits the CIDR block to this group.

    • Use your own IP addresses. For information about bringing your own IP addresses, see Bring your own IP addresses (BYOIP) in the Amazon EC2 User Guide for Linux Instances.

There are differences between an Elastic IP address that you use in a VPC and one that you use in EC2-Classic. For more information, see Differences between EC2-Classic and VPC in the Amazon EC2 User Guide for Linux Instances. You can move an Elastic IP address that you've allocated for use in the EC2-Classic platform to the VPC platform. For more information, see Migrating an Elastic IP address from EC2-Classic.

Elastic IP addresses are regional. For more information about using Global Accelerator to provision global IP addresses, see Using global static IP addresses instead of regional static IP addresses in the AWS Global Accelerator Developer Guide.

Working with Elastic IP addresses

The following sections describe how you can work with Elastic IP addresses.

Allocating an Elastic IP address

Before you use an Elastic IP, you must allocate one for use in your VPC.

Console

To allocate an Elastic IP address for use in a VPC

  1. Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

  2. In the navigation pane, choose Elastic IPs.

  3. Choose Allocate Elastic IP address.

  4. For Public IPv4 address pool choose one of the following:

    • Amazon's pool of IP addresses—If you want an IPv4 address to be allocated from Amazon's pool of IP addresses.

    • My pool of public IPv4 addresses—If you want to allocate an IPv4 address from an IP address pool that you have brought to your AWS account. This option is disabled if you do not have any IP address pools.

    • Customer owned pool of IPv4 addresses—If you want to allocate an IPv4 address from a pool created from your on-premises network for use with an Outpost. This option is not avalable if you do not have an Outpost.

  5. (Optional) Add or remove a tag.

    [Add a tag] Choose Add new tag and do the following:

    • For Key, enter the key name.

    • For Value, enter the key value.

    [Remove a tag] Choose Remove to the right of the tag’s Key and Value.

  6. Choose Allocate.

    Note

    If your account supports EC2-Classic, first choose VPC.

CLI and API

To allocate an Elastic IP address

Associating an Elastic IP address

You can associate an Elastic IP with a running instance or network interface in your VPC.

After you associate the Elastic IP address with your instance, the instance receives a public DNS hostname if DNS hostnames are enabled. For more information, see Using DNS with your VPC.

Console

To associate an Elastic IP address with an instance or network interface in a VPC

  1. Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

  2. In the navigation pane, choose Elastic IPs.

  3. Select an Elastic IP address that's allocated for use with a VPC (the Scope column has a value of vpc), and then choose Actions, Associate Elastic IP address.

  4. Choose Instance or Network interface, and then select either the instance or network interface ID. Select the private IP address with which to associate the Elastic IP address. Choose Associate.

CLI and API

To associate an Elastic IP address with an instance or network interface

Viewing your Elastic IP addresses

You can view the Elastic IP addresses that are allocated to your account.

Console

To view your Elastic IP addresses

  1. Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

  2. In the navigation pane, choose Elastic IPs.

  3. To filter the displayed list, start typing part of the Elastic IP address or one of its attributes in the search box.

CLI and API

To view one or more Elastic IP addresses

Tagging an Elastic IP address

You can apply tags to your Elastic IP address to help you identify it or categorize it according to your organization's needs.

Console

To tag an Elastic IP address

  1. Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

  2. In the navigation pane, choose Elastic IPs.

  3. Select the Elastic IP address and choose Tags.

  4. Choose Manage tags, enter the tag keys and values as required, and choose Save.

CLI and API

To tag an Elastic IP address

Disassociating an Elastic IP address

To change the resource that the Elastic IP address is associated with, you must first disassociate it from the currently associated resource.

Console

To disassociate an Elastic IP address

  1. Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

  2. In the navigation pane, choose Elastic IPs.

  3. Select the Elastic IP address, and then choose Actions, Disassociate Elastic IP address.

  4. When prompted, choose Disassociate.

CLI and API

To disassociate an Elastic IP address

Releasing an Elastic IP address

If you no longer need an Elastic IP address, we recommend that you release it. You incur charges for any Elastic IP address that's allocated for use with a VPC but not associated with an instance. The Elastic IP address must not be associated with an instance or network interface.

Console

To release an Elastic IP address

  1. Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

  2. In the navigation pane, choose Elastic IPs.

  3. Select the Elastic IP address, and then choose Actions, Release Elastic IP addresses.

  4. When prompted, choose Release.

CLI and API

To release an Elastic IP address

Recovering an Elastic IP address

If you release your Elastic IP address, you might be able to recover it. You cannot recover the Elastic IP address if it has been allocated to another AWS account, or if it results in you exceeding your Elastic IP address quota.

You can recover an Elastic IP address using the Amazon EC2 API or a command line tool.

To recover an Elastic IP address using the AWS CLI

Use the allocate-address command and specify the IP address using the --address parameter.

aws ec2 allocate-address --domain vpc --address 203.0.113.3