City application Pods on different worker nodes must communicate us…

Question

City application Pods on different worker nodes must communicate using Pod IPs. What connectivity model should administrators expect from a standard CNI setup (absent NetworkPolicy denials)?

Accepted Answer

Every Pod IP should be reachable from every other Pod across nodes on the cluster network. — The Kubernetes networking model is basically a flat phone book: Pod A can dial Pod B's IP anywhere in the cluster unless policy says otherwise. You should not need a LoadBalancer just for Pod-to-Pod chat.

Answer

Pods can only reach each other after an administrator adds NAT hairpin rules per NodePort.

Answer

Cross-node Pod traffic always requires a LoadBalancer Service as a mandatory hop.

Answer

Pods on different nodes share one IP and rely on host ports for isolation.

City application Pods on different worker nodes must communicate using Pod IPs. What connectivity model should administrators expect from a standard CNI setup (absent NetworkPolicy denials)?

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