Disable Public IP Address Assignment for EC2 Instances

Risk Level: High (not acceptable risk)

Ensure that Amazon EC2 instances such as backend instances are not using public IP addresses in order to prevent Internet exposure. Backend instances are EC2 instances that run behind a load balancer and do not need direct access to the Internet, therefore, do not require public IP addresses.

This rule can help you work with the AWS Well-Architected Framework.

Security

Reliability

Performance
efficiency

Amazon EC2 instances should not get public IP addresses at launch in order to enhance security by reducing the attack surface. Instead, they should be placed in private VPC subnets and accessed through the associated load balancer. This setup ensures that incoming traffic is tightly controlled and monitored.

Audit

To determine if your Amazon EC2 instances use public IP addresses, perform the following operations:

Using AWS Console

01 Sign in to the AWS Management Console.

02 Navigate to Amazon EC2 console available at https://console.aws.amazon.com/ec2/.

03 In the left navigation panel, under Instances, choose Instances.

04 Select the Amazon EC2 instance that you want to examine.

05 Choose the Details tab from the console split panel to access the instance configuration information.

06 In the Instance summary section, check the Public IPv4 address configuration attribute value. If the Public IPv4 address attribute value is set to an IPv4 address, the selected Amazon EC2 instance is using a public IP address that is reachable from the Internet.

07 Repeat steps no. 4 – 6 for each Amazon EC2 instance available within the current AWS cloud region.

08 Change the AWS cloud region from the top navigation bar and repeat the Audit process for other regions.

Using AWS CLI

01 Run describe-instances command (OSX/Linux/UNIX) with custom output filters to list the IDs of the Amazon EC2 instances provisioned in the selected AWS cloud region:

aws ec2 describe-instances
	--region us-east-1
	--output table
	--query 'Reservations[*].Instances[*].InstanceId'

02 The command output should return a table with the requested EC2 instance identifiers (IDs):

-------------------------
|   DescribeInstances   |
+-----------------------+
|  i-01234abcd1234abcd  |
|  i-0abcdabcdabcdabcd  |
|  i-0abcd1234abcd1234  |
+-----------------------+

03 Run describe-instances command (OSX/Linux/UNIX) with the ID of the Amazon EC2 instance that you want to examine as the identifier parameter and custom output filters to determine whether the selected EC2 instance is associated with a public or an Elastic IP address:

aws ec2 describe-instances
	--region us-east-1
	--instance-ids i-01234abcd1234abcd
	--query "Reservations[*].Instances[*].NetworkInterfaces[*].Association.IpOwnerId[] | []"

04 The command output should return an empty array if the verified instance has no public IP address assigned, "amazon" if the instance has a public IP address, or the AWS account ID of the owner if the selected instance is associated with an Elastic IP address:

[
	"amazon"
]

If the describe-instances command output returns an AWS account ID (e.g., "123456789012") or "amazon" (as shown in the output example above), the selected Amazon EC2 instance is using a public or an Elastic IP address that is reachable from the Internet.

05 Repeat steps no. 3 and 4 for each Amazon EC2 instance that you want to examine, available in the selected AWS region.

06 Change the AWS cloud region by updating the --region command parameter value and repeat the Audit process for other regions.

Remediation / Resolution

To disable public IP address assignment for your existing Amazon EC2 instances, you have to re-create your EC2 instances with the appropriate network configuration. To relaunch (re-create) your Amazon EC2 instances, perform the following operations:

Using AWS Console

01 Sign in to the AWS Management Console.

02 Navigate to Amazon EC2 console available at https://console.aws.amazon.com/ec2/.

03 In the left navigation panel, under Instances, choose Instances.

04 Select the Amazon EC2 instance that you want to re-create.

05 Choose Actions from the top-right menu, select Image and templates, and choose Create image.

06 On the Create image setup page, provide the following information:

For Image name, type a unique name for your new Amazon Machine Image (AMI).
(Optional) For Image description - optional, provide a short description that reflects the usage of the selected EC2 instance.
Select the Reboot instance setting checkbox to ensure data consistency. When this option is selected, Amazon EC2 reboots the instance so that data is at rest when snapshots of the attached volumes are taken.
(Optional) For Tags - optional, choose Tag image and snapshots together, and use the Add new tag button to create and apply user-defined tags to the new image. Tags can be used to search and filter your cloud resources or track your AWS costs.
Choose Create image to create your new AMI.

07 In the left navigation panel, under Images, select AMIs, and check the Status column to determine the state of your new AMI. Once the Status is set to Available, the image is ready to be used to relaunch your Amazon EC2 instance in the appropriate Availability Zone (AZ).

08 In the left navigation panel, under Instances, select Instances, choose Launch instances, and perform the following actions to launch your new EC2 instance:

For Name and tags, provide a name tag for your instance in the Name box. (Optional) Choose Add additional tags to apply user-defined tags to your new EC2 instance. You can track compute cost and other criteria by tagging your instance.
For Application and OS Images (Amazon Machine Image), select My AMIs tab, choose Owned by me, and select the name of the AMI created in step no. 6 from the Amazon Machine Image (AMI) dropdown list.
For Instance type, select the required instance type from the Instance type dropdown list (must match the hardware configuration of the source instance).
For Key pair (login), you can select the same key pair as the source instance from the Key pair name - required dropdown list or choose Create new key pair to create a new key pair for your instance.
For Network settings, perform the following actions:
1. Choose Select existing security group under Firewall (security groups), and select the appropriate security group(s) from the Common security groups dropdown list (must match the security group configuration of the source instance).
2. Choose Edit and select the required VPC network, subnet, and Availability Zone. Make sure these settings align with the source instance settings. Choose Disable from the Auto-assign public IP dropdown list to launch the new EC2 instance without a public IP address.
For Configure storage, configure the storage device settings (must match the storage configuration of the source instance).
For Advanced details, configure the advanced settings supported by your EC2 instance (must match the configuration of the source instance).
For Summary, review the instance details, and choose Launch instance to deploy your new, compliant Amazon EC2 instance.
Choose View all instances to view your new EC2 instance. Once the Instance State is set to Running, your new instance is ready to use.

09 (Optional) To stop incurring any charges for your non-compliant (source) instance, you must terminate it. To shut down the instance, perform the following actions:

In the left navigation panel, under Instances, choose Instances.
Select the Amazon EC2 instance that you want to terminate.
Choose Instance state and select Terminate (delete) instance.
In the Terminate (delete) instance confirmation box, review the instance details, then choose Terminate (delete) to terminate the selected EC2 instance.

10 Repeat steps no. 2 – 9 for each Amazon EC2 instance that you want to re-create, available within the current AWS cloud region.

11 Change the AWS cloud region from the console navigation bar and repeat the Remediation process for other regions.

Using AWS CLI

01 Run describe-instances command (OSX/Linux/UNIX) to list the configuration information for the Amazon EC2 instance that you want to re-create (i.e., source instance):

aws ec2 describe-instances
	--region us-east-1
	--instance-ids i-01234abcd1234abcd
	--query 'Reservations[*].Instances[]'

02 The command output should return the configuration information necessary for re-creating your Amazon EC2 instance:

[
	{
		"Architecture": "x86_64",
		"BlockDeviceMappings": [
			{
				"DeviceName": "/dev/xvda",
				"Ebs": {
					"AttachTime": "2025-07-01T11:00:32+00:00",
					"DeleteOnTermination": true,
					"Status": "attached",
					"VolumeId": "vol-0abcd1234abcd1234"
				}
			}
		],
		"EbsOptimized": false,
		"EnaSupport": true,
		"Hypervisor": "xen",
		"NetworkInterfaces": [
			{
				"Association": {
					"IpOwnerId": "amazon",
					"PublicDnsName": "ec2-xxx-xxx-xxx-xxx.compute-1.amazonaws.com",
					"PublicIp": "xxx.xxx.xxx.xxx"
				},
				"Attachment": {
					"AttachTime": "2025-07-01T11:00:31+00:00",
					"AttachmentId": "eni-attach-01234abcd1234abcd",
					"DeleteOnTermination": true,
					"DeviceIndex": 0,
					"Status": "attached",
					"NetworkCardIndex": 0
				},
				"Description": "",
				"Groups": [
					{
						"GroupId": "sg-0abcd1234abcd1234",
						"GroupName": "cc-project5-security-group"
					}
				],
				"Ipv6Addresses": [],
				"NetworkInterfaceId": "eni-01234abcd1234abcd",
				"OwnerId": "123456789012",
				"PrivateDnsName": "ip-172-10-20-30.ec2.internal",
				"PrivateIpAddress": "172.10.20.30",
				"PrivateIpAddresses": [
					{
						"Association": {
							"IpOwnerId": "amazon",
							"PublicDnsName": "ec2-xxx-xxx-xxx-xxx.compute-1.amazonaws.com",
							"PublicIp": "xxx.xxx.xxx.xxx"
						},
						"Primary": true,
						"PrivateDnsName": "ip-172-10-20-30.ec2.internal",
						"PrivateIpAddress": "172.10.20.30"
					}
				],
				"SourceDestCheck": true,
				"Status": "in-use",
				"SubnetId": "subnet-01234abcd1234abcd",
				"VpcId": "vpc-0abcd1234abcd1234",
				"InterfaceType": "interface",
				"Operator": {
					"Managed": false
				}
			}
		],
		"RootDeviceName": "/dev/xvda",
		"RootDeviceType": "ebs",
		"SecurityGroups": [
			{
				"GroupId": "sg-0abcd1234abcd1234",
				"GroupName": "cc-project5-security-group"
			}
		],
		"SourceDestCheck": true,
		"Tags": [
			{
				"Key": "Name",
				"Value": "cc-project5-prod-instance"
			}
		],
		"VirtualizationType": "hvm",
		"CpuOptions": {
			"CoreCount": 1,
			"ThreadsPerCore": 1
		},
		"CapacityReservationSpecification": {
			"CapacityReservationPreference": "open"
		},
		"HibernationOptions": {
			"Configured": false
		},
		"MetadataOptions": {
			"State": "applied",
			"HttpTokens": "required",
			"HttpPutResponseHopLimit": 2,
			"HttpEndpoint": "enabled",
			"HttpProtocolIpv6": "disabled",
			"InstanceMetadataTags": "disabled"
		},
		"EnclaveOptions": {
			"Enabled": false
		},
		"BootMode": "uefi-preferred",
		"PlatformDetails": "Linux/UNIX",
		"UsageOperation": "RunInstances",
		"UsageOperationUpdateTime": "2025-07-01T11:00:31+00:00",
		"PrivateDnsNameOptions": {
			"HostnameType": "ip-name",
			"EnableResourceNameDnsARecord": true,
			"EnableResourceNameDnsAAAARecord": false
		},
		"MaintenanceOptions": {
			"AutoRecovery": "default",
			"RebootMigration": "default"
		},
		"CurrentInstanceBootMode": "legacy-bios",
		"NetworkPerformanceOptions": {
			"BandwidthWeighting": "default"
		},
		"Operator": {
			"Managed": false
		},
		"InstanceId": "i-01234abcd1234abcd",
		"ImageId": "ami-0abcd1234abcd1234",
		"State": {
			"Code": 16,
			"Name": "running"
		},
		"PrivateDnsName": "ip-172-10-20-30.ec2.internal",
		"PublicDnsName": "ec2-xxx-xxx-xxx-xxx.compute-1.amazonaws.com",
		"StateTransitionReason": "",
		"KeyName": "cc-project5-ssh-key",
		"AmiLaunchIndex": 0,
		"ProductCodes": [],
		"InstanceType": "t2.micro",
		"LaunchTime": "2025-07-01T10:01:31+00:00",
		"Placement": {
			"GroupName": "",
			"Tenancy": "default",
			"AvailabilityZone": "us-east-1a"
		},
		"Monitoring": {
			"State": "disabled"
		},
		"SubnetId": "subnet-01234abcd1234abcd",
		"VpcId": "vpc-0abcd1234abcd1234",
		"PrivateIpAddress": "172.10.20.30",
		"PublicIpAddress": "xxx.xxx.xxx.xxx"
	}
]

03 Run create-image command (OSX/Linux/UNIX) to create an Amazon Machine Image (AMI) from the source Amazon EC2 instance described in the previous step. Include the --no-reboot command parameter to ensure data consistency. When this parameter is included, Amazon EC2 reboots the instance so that data is at rest when snapshots of the attached volumes are taken:

aws ec2 create-image
	--region us-east-1
	--instance-id i-01234abcd1234abcd
	--name "Project5 Prod Instance AMI"
	--description "Production Stack AMI version 2.0"
	--no-reboot

04 The command output should return the ID of the new Amazon Machine Image (AMI):

{
	"ImageId": "ami-0abcdabcdabcdabcd"
}

05 Perform run-instances command (OSX/Linux/UNIX) to launch a new Amazon EC2 instance from the AMI created in the previous steps. Use the information returned in step no. 2 to configure your new EC2 instance. Include the --no-associate-public-ip-address parameter in the command request to prevent assigning a public IPv4 address to your new EC2 instance:

aws ec2 run-instances
	--region us-east-1
	--image-id ami-0abcdabcdabcdabcd
	--count 1
	--instance-type t2.micro
	--key-name cc-project5-ssh-key
	--security-group-ids sg-0abcd1234abcd1234
	--subnet-id subnet-0abcd1234abcd1234
	--tag-specifications 'ResourceType=instance,Tags=[{Key=Name,Value=cc-project5-prod-instance}]'
	--no-associate-public-ip-address
	--query 'Instances[]'

06 The command output should return the configuration information for the newly created EC2 instance:

[
	{
		"Architecture": "x86_64",
		"BlockDeviceMappings": [],
		"EbsOptimized": false,
		"EnaSupport": true,
		"Hypervisor": "xen",
		"NetworkInterfaces": [
			{
				"Attachment": {
					"AttachTime": "2025-07-01T11:50:48+00:00",
					"AttachmentId": "eni-attach-01234abcd1234abcd",
					"DeleteOnTermination": true,
					"DeviceIndex": 0,
					"Status": "attaching",
					"NetworkCardIndex": 0
				},
				"Description": "",
				"Groups": [
					{
						"GroupId": "sg-0abcd1234abcd1234",
						"GroupName": "cc-project5-security-group"
					}
				],
				"Ipv6Addresses": [],
				"NetworkInterfaceId": "eni-01234abcd1234abcd",
				"OwnerId": "123456789012",
				"PrivateDnsName": "ip-172-20-30-40.ec2.internal",
				"PrivateIpAddress": "172.20.30.40",
				"PrivateIpAddresses": [
					{
						"Primary": true,
						"PrivateDnsName": "ip-172-20-30-40.ec2.internal",
						"PrivateIpAddress": "172.20.30.40"
					}
				],
				"SourceDestCheck": true,
				"Status": "in-use",
				"SubnetId": "subnet-01234abcd1234abcd",
				"VpcId": "vpc-0abcd1234abcd1234",
				"InterfaceType": "interface",
				"Operator": {
					"Managed": false
				}
			}
		],
		"RootDeviceName": "/dev/xvda",
		"RootDeviceType": "ebs",
		"SecurityGroups": [
			{
				"GroupId": "sg-0abcd1234abcd1234",
				"GroupName": "cc-project5-security-group"
			}
		],
		"SourceDestCheck": true,
		"StateReason": {
			"Code": "pending",
			"Message": "pending"
		},
		"Tags": [
			{
				"Key": "Name",
				"Value": "cc-project5-prod-instance"
			}
		],
		"VirtualizationType": "hvm",
		"CpuOptions": {
			"CoreCount": 1,
			"ThreadsPerCore": 1
		},
		"CapacityReservationSpecification": {
			"CapacityReservationPreference": "open"
		},
		"MetadataOptions": {
			"State": "pending",
			"HttpTokens": "required",
			"HttpPutResponseHopLimit": 2,
			"HttpEndpoint": "enabled",
			"HttpProtocolIpv6": "disabled",
			"InstanceMetadataTags": "disabled"
		},
		"EnclaveOptions": {
			"Enabled": false
		},
		"BootMode": "uefi-preferred",
		"PrivateDnsNameOptions": {
			"HostnameType": "ip-name",
			"EnableResourceNameDnsARecord": false,
			"EnableResourceNameDnsAAAARecord": false
		},
		"MaintenanceOptions": {
			"AutoRecovery": "default",
			"RebootMigration": "default"
		},
		"CurrentInstanceBootMode": "legacy-bios",
		"Operator": {
			"Managed": false
		},
		"InstanceId": "i-0abcd1234abcd1234",
		"ImageId": "ami-0abcdabcdabcdabcd",
		"State": {
			"Code": 0,
			"Name": "pending"
		},
		"PrivateDnsName": "ip-172-20-30-40.ec2.internal",
		"PublicDnsName": "",
		"StateTransitionReason": "",
		"KeyName": "cc-project5-ssh-key",
		"AmiLaunchIndex": 0,
		"ProductCodes": [],
		"InstanceType": "t2.micro",
		"LaunchTime": "2025-07-01T11:50:48+00:00",
		"Placement": {
			"GroupName": "",
			"Tenancy": "default",
			"AvailabilityZone": "us-east-1a"
		},
		"Monitoring": {
			"State": "disabled"
		},
		"SubnetId": "subnet-01234abcd1234abcd",
		"VpcId": "vpc-0abcd1234abcd1234",
		"PrivateIpAddress": "172.20.30.40"
	}
]

07 (Optional) You can terminate the source (non-compliant) EC2 instance in order to stop incurring charges for it. To shut down the instance, run terminate-instances command (OSX/Linux/UNIX) with the source instance ID as the identifier parameter:

aws ec2 terminate-instances
	--region us-east-1
	--instance-ids i-01234abcd1234abcd

08 The output should return the **terminate-instances** command request information:

{
	"TerminatingInstances": [
		{
			"InstanceId": "i-01234abcd1234abcd",
			"CurrentState": {
				"Code": 32,
				"Name": "shutting-down"
			},
			"PreviousState": {
				"Code": 16,
				"Name": "running"
			}
		}
	]
}

09 Repeat steps no. 1 – 8 for each Amazon EC2 instance that you want to re-create, available in the selected AWS cloud region.

10 Change the AWS cloud region by updating the --region command parameter value and repeat the Remediation process for other regions.

References

AWS Documentation
FAQs
Launch an instance using the new launch instance wizard
Elastic IP addresses
IP addressing for your VPCs and subnets

AWS Command Line Interface (CLI) Documentation
describe-instances
create-image
run-instances
terminate-instances

Publication date Sep 4, 2023

Audit

Using AWS Console

Using AWS CLI

Remediation / Resolution

Using AWS Console

Using AWS CLI

References

Related EC2 rules