Explaining Elastic IP Addresses in AWS

#aws #networking #vpc

The aim of this page is to explain AWS Elastic IPs and their uses. I was under the incorrect impression that elasticity means that IPs are changing. Wrong! What's changing is a network resource using that IP, say in a crash a new resource can use the same address quickly. The amount of EIP in a VPC/region is pretty small actually - just 5. Having a case then I need to increase that limit to 7 when deploying resources. Some notes further down:

Error Handling: Indeed, the AddressLimitExceeded error occurs when the maximum EIP limit is reached.
Default Limit: AWS allows up to 5 EIPs per region by default.
Static IP: A static IP does not change over time; useful for consistent access.
Elastic IP (EIP): A static IP that can be reassigned to different instances dynamically.
High Availability: EIPs mask instance failures by quickly remapping to another instance.
Consistent DNS Setup: EIPs ensure DNS names point to the same IP, even if the instance changes.
Load Balancing: EIPs help maintain high availability and reliability for services.
Elasticity: Elasticity refers to the reassignment capability of an EIP, not changing the IP value.
Usage with NAT Gateways: NAT gateways can use EIPs for outbound internet access.
Checking EIP: Verify if a NAT gateway uses an EIP in the AWS VPC Console under NAT Gateway details.