An FC (Fibre Channel) MetroCluster configuration uses a dedicated Fibre Channel SAN fabric for backend storage connectivity and for the Inter-Switch Links (ISLs) between the two sites. Fibre Channel switches are a core component of this architecture, providing the high-speed, low-latency, and reliable transport necessary for synchronous replication between the MetroCluster nodes and their shared storage across distances.

A. Ethernet switches are the primary connectivity method for the cluster interconnect in a MetroCluster IP configuration, not an FC configuration.

C. Wireless networking does not provide the necessary bandwidth, reliability, or low latency required for a high-performance, synchronous storage fabric.

D. Direct SATA connection is an interface protocol used for connecting individual disk drives inside a storage shelf, not for inter-site connectivity.

1. NetApp. (2023). MetroCluster Installation and Configuration Guide for ONTAP 9.13.1. Section: "FC MetroCluster components." This section explicitly lists Fibre Channel switches as a required component for the storage and cluster interconnect fabric.

2. NetApp. (2023). TR-4705: MetroCluster Solution Architecture and Design. Page 11, Figure 2: "Four-node FC MetroCluster configuration." The diagram clearly illustrates the use of Fibre Channel switches for both the local fabric and the inter-site links (ISLs).