# Which of these is required to connect two clusters with Cilium ClusterMesh?

Cilium, Hard (Expert), Architecture. https://k8wiz.com/uquiz/which-of-these-is-required-to-connect-two-clusters-with-cilium-clustermesh

- A. Unique cluster names and IDs, distinct pod CIDRs, node-to-node reachability
- B. A single etcd cluster shared by both Kubernetes control planes
- C. Identical Kubernetes versions and the same node count in both clusters
- D. Istio installed in both clusters to carry cross-cluster traffic

**Answer:** Unique cluster names and IDs, distinct pod CIDRs, node-to-node reachability

**Explanation:** Pods talk across clusters with their real IPs, so pod CIDRs must not overlap and nodes have to reach each other. Each cluster needs a unique cluster.name and cluster.id, which Cilium uses to keep identities apart. Each cluster runs its own clustermesh-apiserver, and the Kubernetes control planes share nothing.