Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 425

• The control VLAN is not used to carry any data traffic; it carries only RHFs. • The control VLAN cannot have members that are not ring ports. • If multiple rings share one or more member VLANs, they cannot share any links between them. • Member VLANs across multiple rings are not supported in Master nodes. • Each ring has only one Master node; all others are transit nodes. Attention: The port extender does not support FRRP. Important FRRP Concepts The following table lists some important FRRP concepts. Concept Explanation Ring ID Each ring has a unique 8-bit ring ID through which the ring is identified (for example, 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 RHF, 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 RHFs. The Master node Secondary port receives the RHFs. On Transit nodes, there is no distinction between a Primary and Secondary interface when operating in the Normal state. Ring Interface 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. • 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. • Disabled State - When the port is disabled or down, or is not on the VLAN. Ring Protocol Timers • Hello Interval - The interval when ring frames are generated from the Master node's Primary interface (default 500 ms). The Hello interval is configurable in 50 ms increments from 50 ms to 2000 ms. • Dead Interval - The interval when data traffic is blocked on a port. The default is three times the Hello interval rate. The dead interval is configurable in 50 ms increments from 50 ms to 6000 ms. Force10 Resilient Ring Protocol (FRRP) 425