ONTAP exposes SNMP at the cluster level. Here's how to enable it and what it's good for versus ONTAP's own REST API.
From the ONTAP CLI, SNMP is enabled and a community is set at the cluster scope, applying to every node.
system snmp community add -type ro -community-name linivoRO system snmp init -community linivoRO
Poll the cluster's management logical interface rather than an individual node IP, since that's what ONTAP's SNMP agent actually answers on and reflects cluster-wide state.
SNMP covers basic health and capacity; ONTAP's REST API exposes per-volume snapshot usage, replication lag and QoS metrics SNMP doesn't carry. Use SNMP for baseline monitoring and add the REST integration if you need that extra depth.