RKE2 to select the faster network interface on both the RKE2 server and agent machines that have two network interfaces

[dekaranger00]

I have a cluster of VMs that have two network interfaces installed. I would like to have RKE2 select the faster network interface for internal cluster communication and use the slower network interface for external communication.

Is there a way to configure the RKE2 to do that? If so, do I need to redeploy the RKE2 cluster to have it pick up the faster network interface?

Thank you.

[brandond]

Kubernetes just selects the interface with the default route. If you want to override that, you can use --node-ip to set the interface of the interface you would prefer to use.

[dekaranger00]

@brandond : Thank you for your reply. That makes sense.

Just to confirm, in addition to --node-ip , I can also use --node-external-ip to set the slower interface to use right?

Then, I also need to tell Canal plugin to use the faster interface by adding a manifest file like below?

# /var/lib/rancher/rke2/server/manifests/rke2-canal-config.yaml
---
apiVersion: helm.cattle.io/v1
kind: HelmChartConfig
metadata:
  name: rke2-canal
  namespace: kube-system
spec:
  valuesContent: |-
    flannel:
      iface: "eth1"

[brandond]

No, node-external-ip is meant for external IPs, if you have an environment where nodes have a publicly accessible address that is NATed to the private address. It may also be used for nodes with one public and one private interface but that's less common.

[dekaranger00]

@brandond: I'm sorry for not making it clear.

In my current environment, the faster interface was set up for nodes in the RKE2 cluster to communicate with each other, and the second slower interface was intended to be used by clients outside of the cluster to reach those nodes from inside the cluster.

In this scenario, don't I need to provide both --node-ip and --node-external-ip by setting the --node-ip to the internal address in the cluster and --node-external-ip to the external address?

Thank you.