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ELB is now ipv6, how to check ipv4 and ipv6 connection and if I am still paying ipv4 addresses?

0

Checklist

  • My website DNS dns has a CNAME record pointing to cloud front distribution
  • the cloud front distribution has as my application load balancer as origin
  • MY EC2 Load balancer is dualstack. It uses 3 dualstack subnets, once for availability zone of my region
  • The task (a webserver) running as FARGATE SPOT instance is running
  • website is reachable, both in http and https, when opened by browser using registered domain name

So 'it works'.

But ... is that enough or there is something other to configure for ipv6 transition? (I know, actually EC2 LB cannot be run as ipv6 only, strange, but ... ok.... )

Is this enough to not pay any ipv4 to amazon? Where can I check there is no public ipv4 assigned to something?

If I enter the single task detail page, is still see a public ipv4 assigned. But why ?! My subnets are configured as is, in cloud formation

  DualStackSubnetA:
    Type: AWS::EC2::Subnet
    Properties:
      # load balancer cannot handle ipv6-only instances, so we use dual-stack subnet configuration
      CidrBlock: 10.0.3.0/24
      # Indicates whether instances launched in this subnet receive a public IPv4 address. The default value is false.
      MapPublicIpOnLaunch: false
      AssignIpv6AddressOnCreation: true
      Ipv6CidrBlock: !Sub
        - ${VpcPart}${SubnetPart}
        - SubnetPart: 00::/64
          VpcPart: !Select
            - 0
            - !Split
              - 00::/56
              - !Select
                - 0
                - !GetAtt VPC.Ipv6CidrBlocks
      AvailabilityZone: !Select
        - 0
        - !GetAZs ""
      VpcId: !Ref VPC
2 Answers
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Hello.

As of May 2023, ALB cannot be configured as IPv6-only.
In other words, it is a dual stack configuration, with public IPv4 and IPv6 configured.
Therefore, I think you will be billed for the public IPv4 associated with ALB.

You can search for public IPv4 in your AWS account using the method described in the AWS blog below.
https://aws.amazon.com/jp/blogs/networking-and-content-delivery/identify-and-optimize-public-ipv4-address-usage-on-aws/

profile picture
EXPERT
answered 7 months ago
  • My problem is not the ipv4 associated with the balancer.

    My problem is that every single task (autoscaled to up to 100 !) actually have a public ipv4 but it's useless, because all tasks are under a load balancer, and so i ELB to reach the tasks, there is no need to have it reachable from outside directly.

  • Isn't public IP enabled in the ECS service settings? Also, if you do not assign a public IP to the Fargate task, you will need to use NAT Gateway or a VPC endpoint to retrieve the container image from ECR. https://docs.aws.amazon.com/AmazonECS/latest/developerguide/networking-outbound.html#networking-private-subnet

0

Hi

Amazon VPC IP Address Manager (IPAM) is a VPC feature that makes it easier for you to plan, track, and monitor IP addresses for your AWS workloads. You can use IPAM automated workflows to more efficiently manage IP addresses.

You can check the charges from the IPAM console https://eu-south-1.console.aws.amazon.com/ipam/home?region=eu-south-1#Dashboard

  • Here is the tool to check IPV6 dig AAAA , Google Dig tool box

Additional Information: https://docs.aws.amazon.com/whitepapers/latest/ipv6-on-aws/scaling-the-dual-stack-network-design-in-aws.html

IPV6 Support

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EXPERT
answered 7 months ago
  • we are not using ipam ast all and your table seems to prove that elb could be ipv6 only, but it's not.

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