Elastic IP
Elastic IP
- When you stop and then start an AWS EC2 instance, it can change it's Public IP
- If you need to have a fixed public IP for your instance, you need an Elastic IP
- An elastic IP is a public [[IPv4]] IP you own as long as you don't delete it
- You can attach to it one instance at a time
- With an Elastic IP address, you can mask the failure of an instance or software by rapidly remapping the address to another instance on your account
- You can only have 5 Elastic IP in your account (you can ask AWS to increase that)
- Overall, try to avoid using Elastic IP
- They often reflect poor [[architectural decisions]]
- Instead, use a random public IP and register a DNS name to it
- Or use a Load Balancer and don't use a public IP at all