From NetApp's Knowledge Base "How to install or update the RCF file on a cDOT Cisco Cluster Switch" so I believe RCF files are for both NetApp and Cisco switches.
NetApp Branded Switches. NetApp has Rebranded Broadcom switches to be used as both Cluster and Management switches. The CN1610 is a 24-port switch that is used as a Cluster switch. The CN1601 is a 24-port switch used as a Management switch.
The Broadcom Switches call CDP, LLDP Link Layer Discovery Protocol. So I think the correct answer is Jumbo Frames & CDP.