is clusterIP accessible from other node?

Question

i saw some statement that clusterIP can not be accessed by external machine outside the cluster.

but i am not sure what the cluster mean here, does it mean cluster of pods or cluster of nodes.

ultimate question, can clusterIP (without node port) be accessed by other nodes?

Thanks

Answer 1

Yes, ClusterIP services can be reached by nodes in the cluster. Part of their purpose is to load-balance across replicas for Pods (which may be in different Nodes) so that traffic isn't all going to particular Pods. See Clarify Ingress load balancer

A ClusterIP service doesn't really live on any single Node but rather on each Node. The kube-proxy on each Node ensures that the load-balancing across instances takes place by updating each Nodes iptables