Is it safe to disable inter-container connectivity (icc) on the Docker daemon in an RKE or Rancher v2.x launched Kubernetes cluster?

Article Number: 000020204

Environment

A Rancher Kubernetes Engine (RKE) cluster, provisioned by the RKE CLI or Rancher v2.x

Situation

The Docker daemon provides a configuration option icc which permits a user to disable inter-container connectivity (icc) on the Docker bridge network. Is is safe to disable this Docker daemon option in an RKE or Rancher v2.x launched Kubernetes cluster?

Resolution

Setting icc to false in the docker daemon.json configuration, or as an argument to to dockerd, is possible but is unnecessary in an RKE or Rancher v2.x provisioned Kubernetes cluster, as containers are not run attached to the Docker bridge network. Therefore, whilst this step is often included in standard 'hardening Docker daemon' guides, it is not relevant to operating an RKE or Rancher launched Kubernetes cluster.