Dell PowerConnect B-RX BigIron RX Series Configuration Guide v02.8.00 - Page 517

VSRP and MRP signaling 15 If a VSRP failover from master to backup occurs, VSRP needs to inform MRP of the topology change; otherwise, data from the host continues along the obsolete learned path and never reach the VSRP-linked device, as shown in Figure 82. FIGURE 82 VSRP on MRP rings that failed over Path 1 MRP Master Path 2 MRP Member MRP Member MRP MRP Member Host MRP Member MRP MRP Member Host MRP Member VSRP Backup X VSRP MRP Member VSRP Master MRP Master VSRP Backup X VSRP MRP Member VSRP Master Device 1 Device 1 To ensure that MRP is informed of the topology change and to achieve convergence rapidly, there is a signaling process that controls the interaction between VSRP and MRP. When a VSRP node fails, a new VSRP master is selected. The new VSRP master finds all MRP instances impacted by the failover. Then each MRP instance does the following: • The MRP node sends out an MRP PDU with the mac-flush flag set three times on the MRP ring. • The MRP node that receives this MRP PDU empties all the MAC address entries from its interfaces that participate on the MRP ring. • The MRP node then forwards the MRP PDU with the mac-flush flag set to the next MRP node that is in forwarding state. The process continues until the Master MRP node's secondary (blocking) interface blocks the packet. Once the MAC address entries have been flushed, the MAC table can be rebuilt for the new path from the host to the VSRP-linked device (Figure 83). BigIron RX Series Configuration Guide 441 53-1002253-01