What is the minimal interface requirement for a SnapMirror relationship between clusters?

For a SnapMirror relationship to function reliably and maintain high availability, NetApp ONTAP requires at least one intercluster logical interface (LIF) to be configured on each node within the cluster. This ensures that if a volume is moved to a different node (either manually or through a high-availability event like a takeover), replication traffic can continue without interruption. The intercluster LIFs provide the dedicated network paths for all intercluster communication, including SnapMirror data transfers. This per-node configuration is a fundamental prerequisite for establishing a cluster peer relationship.

A. one data LIF per SVM: Data LIFs are intended for client-facing traffic (NFS, SMB, iSCSI), not for the backend replication traffic between clusters. Using them for replication is not a supported best practice.

B. one cable directly connected to both clusters: This describes a physical topology, not the logical interface requirement. Intercluster relationships can operate over complex routed networks, not just direct connections.

D. one intercluster LIF per SVM: Intercluster LIFs are node-scoped resources, not SVM-scoped. They are created on the physical nodes of the cluster to serve all SVMs that require intercluster connectivity.

1. NetApp ONTAP 9 Documentation, Network and LIF management, "Create intercluster LIFs": "Before you can create a cluster peer relationship, you must create at least one intercluster logical interface (LIF) on a network port on each node in the cluster." This statement explicitly defines the minimal requirement.

2. NetApp Technical Report 4182 (TR-4182), "SnapMirror Configuration and Best Practices Guide for ONTAP 9.3": In Section 3.1, "Intercluster Network Configuration," the guide states: "For each node in the cluster, create at least one intercluster LIF for each IPspace that is used for replication." This reinforces the per-node requirement as a best practice for a functional setup.

3. NetApp ONTAP 9 Documentation, Data protection, "Prerequisites for cluster peering": The documentation lists as a prerequisite: "Intercluster LIFs are configured on all nodes of the local and remote clusters." This confirms it is a mandatory step before peering can be established for SnapMirror.