Reference Guide

Force10 Resilient Ring Protocol (FRRP) | 369
Important FRRP Points
FRRP provides a convergence time that can generally range between 150ms and 1500ms for Layer 2
networks. The master node originates a high-speed frame that circulates around the ring. This frame,
appropriately, sets up or breaks down the ring.
• 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 per ring—all other nodes are Transit
• Each node has 2 member interfaces —Primary, Secondary
• No limit to the number of nodes on a ring
• Master node ring port states—blocking, pre-forwarding, forwarding, disabled
• 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 17-1 lists some important FRRP concepts.
Table 17-1. FRRP Components
Concept Explanation
Ring 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 the illustration in Member VLAN
Spanning Two Rings Connected by One Switch.
Control VLAN 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.
Member VLAN Each ring maintains a list of member VLANs. Member VLANs must be
consistent across the entire ring.
Port Role 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.