> For the complete documentation index, see [llms.txt](https://cortex-docs.paloaltonetworks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cortex-docs.paloaltonetworks.com/appsec-rules/iac-security/public-exposure/appsec2-aws-19.md).

# Not all EIP addresses allocated to a VPC are attached to EC2 instances misconfiguration detected in

## Rule Details

|                        |                                |
| ---------------------- | ------------------------------ |
| Cortex AppSec Rule ID  | APPSEC2\_AWS\_19               |
| Category - Subcategory | Public Exposure - VPC VCN VNet |
| Provider               | AWS                            |
| Severity               | LOW                            |
| Framework              | Terraform, Terraform Plan      |

## Impact

Ensure that an Elastic IP (EIP) is allocated for each NAT gateway that you want to deploy within your AWS account. An EIP address is a static, public IP address designed for dynamic cloud computing. You can associate an AWS EIP address with any EC2 instance, VPC ENI or NAT gateway. A Network Address Translation (NAT) gateway is a device that helps enabling EC2 instances in a private subnet to connect to the Internet and prevent the Internet from initiating a connection with those instances. With Elastic IPs, you can mask the failure of an EC2 instance by rapidly remapping the address to another instance launched in your VPC

## How to Fix

*Resource:* aws\_eip, aws\_instance

* *Arguments:* *instance* and *vpc* of aws\_eip \[source,go]

***

{ "resource "aws\_eip" "ok\_eip" { instance = aws\_instance.ec2.id vpc = true }

resource "aws\_instance" "ec2" { ami = "ami-21f78e11" availability\_zone = "us-west-2a" instance\_type = "t2.micro"

tags = { Name = "HelloWorld" }

## } ", }


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