Dell Force10 S55T S55 Configuration Guide FTOS 8.3.5.3 - Page 257

• Transit node ring port states-blocking, pre-forwarding, forwarding, disabled • STP disabled on ring interfaces • 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 nodes Important FRRP Concepts Table 12-1 lists some important FRRP concepts. Table 12-1. FRRP Components Concept Ring ID Control VLAN Member VLAN Port Role Ring Interface State Explanation 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 12-2. Each ring has a unique Control VLAN through which tagged Ring Health Frames (RHF) are sent. Control VLANs are used only for sending Ring Health Frames, and cannot be used for any other purpose. Each ring maintains a list of member VLANs. Member VLANs must be consistent across the entire ring. Each node has two ports for each ring: Primary and Secondary. The Master node Primary port generates Ring Health Frames (RHF). The Master node Secondary port receives the RHF frames. On Transit nodes, there is no distinction between a Primary and Secondary interface when operating in the Normal state. Each interface (port) that is part of the ring maintains one of four states • Blocking State: Accepts ring protocol packets but blocks data packets. LLDP, FEFD, or other Layer 2 control packets are accepted. Only the master node Secondary port can enter this state. • Pre-Forwarding State: A transition state before moving to the Forward state. Control traffic is forwarded but data traffic is blocked. The Master node Secondary port transitions through this state during ring bring-up. All ports transition through this state when a port comes up. • Forwarding State-Both ring control and data traffic is passed. When the ring is in Normal operation, the Primary port on the Master node and both Primary and Secondary ports on the Transit nodes are in forwarding state. When the ring is broken, all ring ports are in this state. • Disabled State-When the port is disabled or down, or is not on the VLAN. Dell Force10 Resilient Ring Protocol | 257