Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 380

Member VLAN Spanning Two Rings Connected by One Switch A member VLAN can span two rings interconnected by a common switch, in a figure-eight style topology. A switch can act as a Master node for one FRRP group and a Transit for another FRRP group, or it can be a Transit node for both rings. In the following example, FRRP 101 is a ring with its own Control VLAN, and FRRP 202 has its own Control VLAN running on another ring. A Member VLAN that spans both rings is added as a Member VLAN to both FRRP groups. Switch R3 has two instances of FRRP running on it: one for each ring. The example topology that follows shows R3 assuming the role of a Transit node for both FRRP 101 and FRRP 202. 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. • The Master node transmits ring status check frames at specified intervals. • You can run multiple physical rings on the same switch. • One Master node per ring - all other nodes are Transit. • Each node has two member interfaces - primary and secondary. • There is no limit to the number of nodes on a ring. • Master node ring port states - blocking, pre-forwarding, forwarding, and disabled. • Transit node ring port states - blocking, pre-forwarding, forwarding, and 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); Only the Master node transmits and processes these. - Topology Change RHF: triggered updates; processed at all nodes. Implementing FRRP • FRRP is media and speed independent. • FRRP is a Dell proprietary protocol that does not interoperate with any other vendor. • You must disable the spanning tree protocol (STP) on both the Primary and Secondary interfaces before you can enable FRRP. • All ring ports must be Layer 2 ports. This is required for both Master and Transit nodes. • A VLAN configured as a control VLAN for a ring cannot be configured as a control or member VLAN for any other ring. • 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. Force10 Resilient Ring Protocol (FRRP) 380