Can I assign Elastic IPs to a Network Load Balancer (NLB) in an EKS Auto Mode cluster?

Question

Hello,

I’m currently experimenting with EKS Auto Mode to evaluate if I can migrate my existing workloads from a standard EKS cluster. In my current setup, I use the `service.beta.kubernetes.io/aws-load-balancer-eip-allocations` annotation to assign static Elastic IP addresses (EIPs) to the Network Load Balancers (NLBs) created for my Kubernetes Service resources of type LoadBalancer.

Having NLBs with fixed EIPs is important to my environment.

Is it possible to assign Elastic IPs to NLBs in EKS Auto Mode using this annotation, or any other supported method?
If not, are there any recommended approaches or workarounds to achieve reserved/static IPs for LoadBalancer Services in EKS Auto Mode clusters?

Any official documentation, best practices, or alternative solutions would be greatly appreciated!

Thank you!

TheQuietBuilder · Accepted Answer

Great question — and you're ahead of the curve for even testing this in EKS Auto Mode.

As of now, EKS Auto Mode doesn’t support custom annotations like service.beta.kubernetes.io/aws-load-balancer-eip-allocations. Since infrastructure provisioning is fully managed in Auto Mode, there’s currently no supported way to specify Elastic IPs for NLBs like you can in standard EKS clusters.

If having fixed IPs is critical, you’ll probably need to stick with standard EKS, where you retain full control over service annotations and can attach pre-allocated EIPs.

This is a common concern, so you might also want to check out or contribute to the AWS Containers Roadmap — it’s a helpful place to track feature requests and community feedback.

re:Post Agent · Answer

When you create a Kubernetes service of type `LoadBalancer` in EKS Auto Mode, EKS automatically provisions and configures an AWS Network Load Balancer based on the annotations you specify. This declarative approach allows you to manage load balancer configurations directly through your Kubernetes manifests.

While the provided sources don't specifically mention the `service.beta.kubernetes.io/aws-load-balancer-eip-allocations` annotation for assigning Elastic IPs to NLBs in EKS Auto Mode, they do indicate that EKS Auto Mode supports various service annotations for customizing NLB behavior.

EKS Auto Mode handles Network Load Balancer provisioning by default for all services of type LoadBalancer without requiring additional controller installation or configuration. The `loadBalancerClass: eks.amazonaws.com/nlb` specification is automatically set as the cluster default.

For IP targeting in NLBs with EKS Auto Mode, you can use the annotation `service.beta.kubernetes.io/aws-load-balancer-nlb-target-type: ip` in your Service's manifest when configuring your Kubernetes Service of type LoadBalancer.

Since the documentation doesn't explicitly address Elastic IP allocation for NLBs in EKS Auto Mode, I would recommend reaching out to AWS Support for confirmation on whether the `service.beta.kubernetes.io/aws-load-balancer-eip-allocations` annotation is supported in EKS Auto Mode or if there are alternative approaches to achieve static IPs for your LoadBalancer services.  
**Sources**  
[Use Service Annotations to configure Network Load Balancers - Amazon EKS](https://docs.aws.amazon.com/eks/latest/userguide/auto-configure-nlb.html)  
[Load Balancing - Amazon EKS](https://docs.aws.amazon.com/eks/latest/best-practices/load-balancing.html)

Can I assign Elastic IPs to a Network Load Balancer (NLB) in an EKS Auto Mode cluster?

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