Elastic ip

• An Elastic IP address is a static IPv4 address designed for dynamic cloud computing.

• 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.

• To use an Elastic IP address, you first allocate one to your account, and then associate it with your instance or a network interface.

• When you associate an Elastic IP address with an instance or its primary network interface, the instance's public IPv4 address (if it had one) is released back into Amazon's pool of public IPv4 addresses. You cannot reuse a public IPv4 address.

• A disassociated Elastic IP address remains allocated to your account until you explicitly release it. If an Elastic IP address is not associated with a running instance, or if it is associated with a stopped instance or an unattached network interface it will be charged. An Elastic IP address is region specific.

• When you associate an Elastic IP address with an instance that previously had a public IPv4 address, the public DNS hostname of the instance changes to match the Elastic IP address.

• 5 Elastic IP addresses per region.