How many cluster ports does each node have by default?

One cluster port per node would not provide redundancy for cluster interconnect traffic, and this does not match the default ONTAP port configuration.

By default, each ONTAP cluster node is provisioned with two dedicated cluster interconnect ports - typically labeled e0a and e0b on many platforms - that form the cluster network. These ports carry cluster heartbeat traffic, storage failover communication, and internal data replication between nodes. Having two ports provides redundancy for the cluster interconnect so that a single port failure does not isolate a node from the cluster.

Three cluster ports is not the default configuration - ONTAP uses two cluster ports per node by default to balance redundancy and resource usage.

Four cluster ports per node is not the default - some high-performance or special configurations may use more ports, but the standard default is two.