View Amazon EKS security group requirements for clusters - Amazon EKS
Default cluster security groupRestricting cluster trafficShared security groups

View Amazon EKS security group requirements for clusters

This topic describes the security group requirements of an Amazon EKS cluster.

Default cluster security group

When you create a cluster, Amazon EKS creates a security group that’s named eks-cluster-sg-my-cluster-uniqueID . This security group has the following default rules:

Rule type Protocol Ports Source Destination

Inbound

All

All

Self

Outbound

All

All

0.0.0.0/0(IPv4) or ::/0 (IPv6)
Important

If your cluster doesn’t need the outbound rule, you can remove it. If you remove it, you must still have the minimum rules listed in Restricting cluster traffic. If you remove the inbound rule, Amazon EKS recreates it whenever the cluster is updated.

Amazon EKS adds the following tags to the security group. If you remove the tags, Amazon EKS adds them back to the security group whenever your cluster is updated.

Key Value

kubernetes.io/cluster/my-cluster

owned

aws:eks:cluster-name

my-cluster

Name

eks-cluster-sg-my-cluster-uniqueid

Amazon EKS automatically associates this security group to the following resources that it also creates:

  • 2–4 elastic network interfaces (referred to for the rest of this document as network interface) that are created when you create your cluster.

  • Network interfaces of the nodes in any managed node group that you create.

The default rules allow all traffic to flow freely between your cluster and nodes, and allows all outbound traffic to any destination. When you create a cluster, you can (optionally) specify your own security groups. If you do, then Amazon EKS also associates the security groups that you specify to the network interfaces that it creates for your cluster. However, it doesn’t associate them to any node groups that you create.

You can determine the ID of your cluster security group in the AWS Management Console under the cluster’s Networking section. Or, you can do so by running the following AWS CLI command.

aws eks describe-cluster --name my-cluster --query cluster.resourcesVpcConfig.clusterSecurityGroupId

Restricting cluster traffic

If you need to limit the open ports between the cluster and nodes, you can remove the default outbound rule and add the following minimum rules that are required for the cluster. If you remove the default inbound rule, Amazon EKS recreates it whenever the cluster is updated.

Rule type Protocol Port Destination

Outbound

TCP

443

Cluster security group

Outbound

TCP

10250

Cluster security group

Outbound (DNS)

TCP and UDP

53

Cluster security group

You must also add rules for the following traffic:

  • Any protocol and ports that you expect your nodes to use for inter-node communication.

  • Outbound internet access so that nodes can access the Amazon EKS APIs for cluster introspection and node registration at launch time. If your nodes don’t have internet access, review Deploy private clusters with limited internet access for additional considerations.

  • Node access to pull container images from Amazon ECR or other container registries APIs that they need to pull images from, such as DockerHub. For more information, see AWS IP address ranges in the AWS General Reference.

  • Node access to Amazon S3.

  • Separate rules are required for IPv4 and IPv6 addresses.

  • If you are using hybrid nodes, you must add an additional security group to your cluster to allow communication with your on-premises nodes and pods. For more information, see Prepare networking for hybrid nodes.

If you’re considering limiting the rules, we recommend that you thoroughly test all of your Pods before you apply your changed rules to a production cluster.

If you originally deployed a cluster with Kubernetes 1.14 and a platform version of eks.3 or earlier, then consider the following:

  • You might also have control plane and node security groups. When these groups were created, they included the restricted rules listed in the previous table. These security groups are no longer required and can be removed. However, you need to make sure your cluster security group contains the rules that those groups contain.

  • If you deployed the cluster using the API directly or you used a tool such as the AWS CLI or AWS CloudFormation to create the cluster and you didn’t specify a security group at cluster creation, then the default security group for the VPC was applied to the cluster network interfaces that Amazon EKS created.

Shared security groups

Amazon EKS supports shared security groups.

  • Security Group VPC Associations associate security groups with multiple VPCs in the same account and region.

  • Shared security groups enable you to share security groups with other AWS accounts. The accounts must be in the same AWS organization.

  • Security groups are always limited to a single AWS region.

Considerations for Amazon EKS

  • EKS has the same requirements of shared or multi-VPC security groups as standard security groups.