Dell Force10 Z9000 FTOS Configuration Guide for Z9000 System - Page 342

www.dell.com | support.dell.com Each Transit node is also configured with a Primary port and a Secondary port on the ring, but the port distinction is ignored as long as the node is configured as a Transit node. If the ring is complete, the Master node logically blocks all data traffic in the transmit and receive directions on the Secondary port to prevent a loop. If the Master node detects a break in the ring, it unblocks its Secondary port and allows data traffic to be transmitted and received through it. See Figure 16-1 for a simple example of this FRRP topology. Note that ring direction is determined by the Master node's Primary and Secondary ports. Figure 16-1. Normal Operating FRRP Topology R2 TRANSIT Ring Direction Primary Forwarding Secondary Forwarding Primary Forwarding Primary Forwarding Secondary R1 Blocking MASTER Secondary Forwarding R3 TRANSIT A Virtual LAN (VLAN) is configured on all node ports in the ring. All ring ports must be members of the Member VLAN and the Control VLAN. The Member VLAN is the VLAN used to transmit data as described earlier. The Control VLAN is used to perform the health checks on the ring. The Control VLAN can always pass through all ports in the ring, including the secondary port of the Master node. Ring Status The Ring Failure notification and the Ring Status checks provide two ways to ensure the ring remains up and active in the event of a switch or port failure. Ring Checking At specified intervals, the Master Node sends a Ring Health Frame (RHF) through the ring. If the ring is complete, the frame is received on its secondary port, and the Master node resets its fail-period timer and continues normal operation. 342 | Force10 Resilient Ring Protocol (FRRP)