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

What is the use of EIP?

EIP provides you with an independent public network IP and bandwidth to implement intercommunication with the Internet. An EIP can be flexibly linked to or disconnected from a VPC-type ECS instance, NAT gateway, Server Load Balancer, and VPN. The bandwidth can be adjusted based on service changes.

How do I know if an EIP is used?

Check to See if an Instance is Using an EIP

The easiest way to check whether or not an instance is using an EIP is to see if the public DNS name and (Public) IP address match your Elastic IP.