Force10 Resilient Ring Protocol | 339• Ring Status Check Frames are transmitted by the Master Node at specified intervals.• Multiple physical rings can be run on the same switch.• One Master node is supported per ring. All other nodes are Transit nodes.• Each node has 2 member interfaces: Primary and Secondary.• There is no limit to the number of nodes on a ring.• The Master node ring port states are: blocking, pre-forwarding, forwarding, and disabled.• The Transit node ring port states are: blocking, pre-forwarding, forwarding, and disabled/• STP is disabled on ring interfaces.• The Master node secondary port is in blocking state during Normal operation.• Ring Health Frames (RHF)• Hello RHF— Sent at 500ms (hello interval)— Transmitted and processed by Master node only• Topology Change RHF— Triggered updates— Processed at all nodesImportant FRRP ConceptsTable 15-1 lists some important FRRP concepts.Table 15-1. FRRP ComponentsConcept ExplanationRing ID Each ring has a unique 8-bit ring ID through which the ring is identified (e.g.FRRP 101 and FRRP 202 as shown in Figure 15-2.Control VLAN Each ring has a unique Control VLAN through which tagged Ring HealthFrames (RHF) are sent. Control VLANs are used only for sending Ring HealthFrames, and cannot be used for any other purpose.Member VLAN Each ring maintains a list of member VLANs. Member VLANs must beconsistent across the entire ring.Port Role Each node has two ports for each ring: Primary and Secondary. The Master nodePrimary port generates Ring Health Frames (RHF). The Master node Secondaryport receives the RHF frames. On Transit nodes, there is no distinction betweena Primary and Secondary interface when operating in the Normal state.